Monolayer Of Atoms Research Articles

The influence of the condensation rate on the structure of Cu-Mo pseudoalloys

The structure and microhardness of Cu-0.3 at. % Mo vacuum condensates obtained at different deposition rates, both in the initial state and after isothermal annealings carried out up to 800 °C, were studied in the work. It has been established that molybdenum has a dispersing effect on the grain structure of the copper matrix, which consists of the blocking effect of monoatomic molybdenum adsorption layers formed on the surface of growing copper grains during the condensation of a two-component vapor. The structure of Cu-0.3 at. % Mo condensates demonstrates increased thermal stability, retaining the size of the original grain upon annealing up to 800 °C. The thermal stabilization of the grain structure of condensates is explained by the influence of grain-boundary segregations of molybdenum atoms and particles, which reduce the free energy of grain boundaries and the rate of their migration.

Blue phosphorene on Au(111): theoretical, spectroscopic and diffraction analysis reveal the role of single Au adatoms.

In investigating the monoatomic layers of P, several stable two-dimensional (2D) allotropes have been theoretically predicted. Among them, single-layer blue phosphorus (BlueP) appears to deliver promising properties. After initial success, where the structure of BlueP triangular patches on Au(111) was conceived on the basis of scanning tunneling microscopy (STM) and density functional theory (DFT), the surface structure model was revisited multiple times with increasing accuracy and insight of theoretical calculations and experimental datasets. Interestingly, the quest for a reliable atomic structure model of BlueP on Au(111) turned out to be very contentious and challenging, particularly considering the possible incorporation of Au atoms in the 2D sheet of P. This article proposes an extended report on theoretical findings that can be extracted from DFT calculations of the orbital projected band structure and employed for an efficient comparison protocol between the calculations and experimental datasets obtained from angle-resolved photoemission spectroscopy (ARPES). The findings, together with experimental and simulated data from STM imaging and surface X-ray diffraction (SXRD), show a clear way to verify the presence and characterize the stabilizing effect of foreign atoms in 2D materials.

Prominently enhanced luminescence from a continuous monolayer of transition metal dichalcogenide on all-dielectric metasurfaces

Abstract 2D materials such as transition metal dichalcogenides (TMDCs) are a new class of atomic-layer materials possessing optical and electric properties that significantly depend on the number of layers. Electronic transitions can be manipulated in artificial resonant electromagnetic (EM) fields using metasurfaces and other designed nanostructures. Here, we demonstrate prominently resonant enhancement in the photoluminescence (PL) of atomic monolayer, WS2, doped with a small quantity of Mo. The excitonic PL showed a strong enhancement effect on a higher-order magnetic resonance of all-dielectric metasurfaces consisting of periodic arrays of Si nanopellets. The PL intensity witnessed a 300-fold enhancement compared to the reference PL intensity on a flat silicon dioxide (SiO2) layer, which suggests a drastic change in the dynamics of photoexcited states. Confocal PL microscopy and the analysis revealed that the single photons were coherently emitted from the TMDC monolayer on the metasurface. Furthermore, examining the PL lifetime in the ps and ns timescales clarified two exponential components at the prominent exciton PL: a short-time component decaying in 22 ps and a long-time component lasting over 10 ns. Therefore, we can infer that the radiative components were significantly activated in the TMDC monolayer on the metasurfaces in comparison to the reference monolayer on a flat SiO2 layer.

Magnetic properties and structural phase transition in ultrathin fcc Fe(111) and bcc Fe(111) films: First-principles study

The aim of this work is to investigate the structural and magnetic characteristics of Fe thin films with a triangular (hexagonal) lattice surfaces (fcc (111) and bcc (111)). The properties of these structures have been calculated using density functional theory (DFT) implemented in the full-potential local-orbital (FPLO) code. The results indicate a structural phase transition from fcc to bcc structure when the film thickness exceeds 23 Fe atomic monolayers. The considered fcc films prefer the low-spin ferromagnetic state with an average magnetic moment of about 1.0 μB per atom. This moment decreases with increasing film thickness until the critical thickness, where, after the structural transition to the bcc phase, it reaches a value close to that of bulk bcc Fe. Moreover, the values of the magnetic anisotropy energy are positive (perpendicular magnetic anisotropy) for the entire thickness range of films with fcc structure (in ferromagnetic low-spin state) and systematically decrease with increasing film thickness. The presented computational results explain the experimentally observed structural transition and may help to select appropriate substrates with suitable lattice parameters for the deposition of ultrathin Fe(111) films.

Kinkless Electronic Junction along 1D Electronic Channel Embedded in a Van Der Waals Layer.

Here, the formation of type-I and type-II electronic junctions with or without any structural discontinuity along a well-defined 1 nm-wide 1D electronic channel within a van der Waals layer is reported. Scanning tunneling microscopy and spectroscopy techniques are employed to investigate the atomic and electronic structure along peculiar domain walls formed on the charge-density-wave phase of 1T-TaS2 . Distinct kinds of abrupt electronic junctions with discontinuities of the band gap along the domain walls are found, some of which even do not have any structural kinks and defects. Density-functional calculations reveal a novel mechanism of the electronic junction formation; they are formed by a kinked domain wall in the layer underneath through substantial electronic interlayer coupling. This work demonstrates that the interlayer electronic coupling can be an effective control knob over nanometer-scale electronic property of 2D atomic monolayers.

A Gate-Tunable Ambipolar Quantum Phase Transition in a Topological Excitonic Insulator.

Coulomb interactions among electrons and holes in 2D semimetals with overlapping valence and conduction bands can give rise to a correlated insulating ground state via exciton formation and condensation. One candidate material in which such excitonic state uniquely combines with non-trivial band topology are atomic monolayers of tungsten ditelluride (WTe2 ), in which a 2D topological excitonic insulator (2D TEI) forms. However, the detailed mechanism of the 2D bulk gap formation in WTe2 , in particular with regard to the role of Coulomb interactions, has remained a subject of ongoing debate. Here, it shows that WTe2 is susceptible to a gate-tunable quantum phase transition, evident from an abrupt collapse of its 2D bulk energy gap upon ambipolar field-effect doping. Such gate tunability of a 2D TEI, into either n- and p-type semimetals, promises novel handles of control over non-trivial 2D superconductivity with excitonicpairing.

A review on synthesis of graphene oxide and its functionalization through ion irradiation methods

Graphene is a monoatomic layer of sp2 hybridized carbon atoms, which is two-dimensional and has unique electrical, magnetic and mechanical properties. Pristine graphene is inert in nature and limited in its applications. Doping can enhance the properties of graphene. Several efforts have been done recently to tune its properties through doping, which will provide precise control over its structure and properties. In this review, different methods of doping graphene especially chemical versus irradiation methods and their effects are summarized. Moreover, the advantages of ion irradiation techniques in doping are also discussed based on the available experimental results.

Quantum Plasmonics in Sub-Atom-Thick Optical Slots.

We show using time-dependent density functional theory (TDDFT) that light can be confined into slot waveguide modes residing between individual atomic layers of coinage metals, such as gold. As the top atomic monolayer lifts a few Å off the underlying bulk Au (111), ab initio electronic structure calculations show that for gaps >1.5 Å, visible light squeezes inside the empty slot underneath, giving optical field distributions 2 Å thick, less than the atomic diameter. Paradoxically classical electromagnetic models are also able to reproduce the resulting dispersion for these subatomic slot modes, where light reaches in-plane wavevectors ∼2 nm-1 and slows to <10-2c. We explain the success of these classical dispersion models for gaps ≥1.5 Å due to a quantum-well state forming in the lifted monolayer in the vicinity of the Fermi level. This extreme trapping of light may explain transient "flare" emission from plasmonic cavities where Raman scattering of metal electrons is greatly enhanced when subatomic slot confinement occurs. Such atomic restructuring of Au under illumination is relevant to many fields, from photocatalysis and molecular electronics to plasmonics and quantum optics.

Atomistic mechanism of AlCu thin film alloy growth on trenched Si substrate

Molecular dynamics simulation was employed to study the growth mechanisms of an AlCu thin film on a trenched Si(001) substrate. The atomic interactions between Al, Cu, and Si atoms were described by using the Modified Embedded Atom Method (MEAM). This investigation focused on examining the effect of both incident energy and trench heights on the structure, and the morphology of deposited AlCu thin film. The results reveal that the growth mode follows an island mode, and the AlCu film surface exhibits both non-flat and non-uniform texture. The increase in the trench height leads to a more pronounced change in surface morphology and roughness. However, a higher incident energy can significantly reduce the surface roughness due to the mobility of deposited atoms. In addition, a mixing region was observed at the interface between the film and substrate. It is revealed that increasing the incident energy leads to deeper penetration of Al and Cu atoms into the substrate. More importantly, Al atoms penetrate deeper than the Cu atoms. On the other hand, deposition on a trench with 15 monoatomic layers leads to the formation of voids in the film. However, these voids disappear with higher incident energy. The microstructural evolution during deposition film was also analyzed based on the radial distribution function. The results of this function indicate that changes in trench height and the energy of incident adatoms do not significantly influence the structure of the film.

Structural Properties of Graphene

Graphene, a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice with six carbon atoms, are of two types due to their bonding. Due to its structural uniqueness, properties of the grapheme is found to be very different and important in application point of view. Hence, the authors have studied the structural properties as co-ordination number, coordinates, distances of nearest atoms from 1st to 5th, analytically using two dimensional coordinate system taking one atom of a unit cell at the origin. Furthermore, packing fraction is also calculated, as the property is very important to study absorption/adsorption of different atoms into the sheet of it.

Graphene‐Based Nano Materials: Biomedical Applications

AbstractGraphene is a single layered two‐dimensional structure of graphite and it has been a flaming topic of research due to its remarkable properties. The efficiency of graphene‐based materials is exploited in many spheres of life ranging from biosensing, targeted drug delivery, bio‐imaging, quantum physics, transportation, energy storage devices, faster electronics, and many more. Graphene is made of a monolayer of sp2 carbon atoms organized in a hexagonal pattern with a C−C bond length of 1.42 A. Graphene has attracted interest in the development of electrochemical sensors and biosensors due to its excellent electrical conductivity, significant surface area, and high electron transfer potential. Because of these exclusive characteristics, it has also become a suitable contender for extensive biomedical uses that favors the differentiation of human mesenchymal stem cells (MSC) into bone cells and inhibit proliferation of cells, fluorescence quenching, drug/gene delivery, tissue engineering and antitumor treatments. In last ten years, notable research has been conducted to explore its biomedical applications. Encouraged by its numerous successful integrations into the biomedical fields, the up‐to‐date developments of graphene applications in various dimensions of biomedical field such as biosensors, gene and drug delivery, photo‐thermal therapy, bio‐imaging and tissue engineering are summarized here.

Computer simulation of Fe epitaxial films on a Cu(100) substrate

The article addresses the problem of modeling thin epitaxial iron films on a Cu (100) substrate by calculating the surface potential. The purpose of the simulation is to determine the film structure. The model uses the paired Lennard-Jones potential to describe the interatomic interaction. We calculate the surface potential of the copper substrate using the first 10 surface atomic layers. The iron atoms in the first layer are placed in the minima of the surface potential. The surface potential of the monoatomic iron layer and the 9 copper layers underneath determine the position of the second iron layer. The position of atoms in the following layers is formed on the basis of similar calculations. Calculations show that the copper substrate stabilizes the fcc crystal lattice in the iron film at low temperatures. Bulk iron samples at low temperatures have a bcc crystal lattice. The period of the iron lattice along the substrate is equal to the period of the copper lattice. The crystal lattice period of iron perpendicular to the substrate has an intermediate value between the values for copper and for γ-ferrum. The interface effect causes additional vertical deformations in the first two layers of iron above the substrate.

STUDY OF EXTRAORDINARY PHASE TRANSITION IN THIN ANTI-FERROMAGNETIC FILMS: COMPUTER SIMULATION

In the article, an extraordinary phase transition in thin antiferromagnetic films was investigated by computer modeling. The simulation uses the Ising model and Metropolis algorithm. Cubic crystal lattice epitaxial films containing multiple monoatomic layers are studied in the paper. The difference in the value for the exchange integrals in the bulk and on the surface of the film is a condition for the appearance of surface and extraordinary phase transitions. The film shall contain at least eight monoatomic layers for appearance of surface and extraordinary phase transitions. The extraordinary phase transition is investigated at different film thicknesses. Magnetic susceptibility demonstrates a logarithmic dependence on Neel temperature near the phase transition point. The dependence of the critical exponent of magnetic susceptibility on film thickness is calculated for the logarithmic phase.

Cold Cathodes with Two-Dimensional van der Waals Materials.

Two-dimensional van der Waals materials could be used as electron emitters alone or stacked in a heterostructure. Many significant phenomena of two-dimensional van der Waals field emitters have been observed and predicted since the landmark discovery of graphene. Due to the wide variety of heterostructures that integrate an atomic monolayer or multilayers with insulator nanofilms or metallic cathodes by van der Waals force, the diversity of van der Waals materials is large to be chosen from, which are appealing for further investigation. Until now, increasing the efficiency, stability, and uniformity in electron emission of cold cathodes with two-dimensional materials is still of interest in research. Some novel behaviors in electron emission, such as coherence and directionality, have been revealed by the theoretical study down to the atomic scale and could lead to innovative applications. Although intensive emission in the direction normal to two-dimensional emitters has been observed in experiments, the theoretical mechanism is still incomplete. In this paper, we will review some late progresses related to the cold cathodes with two-dimensional van der Waals materials, both in experiments and in the theoretical study, emphasizing the phenomena which are absent in the conventional cold cathodes. The review will cover the fabrication of several kinds of emitter structures for field emission applications, the state of the art of their field emission properties and the existing field emission model. In the end, some perspectives on their future research trend will also be given.

(Invited) Gate Stack Design for Field-Effect Transistors Based on Two-Dimensional Materials

1.Introduction Two-dimensional(2D) materials hold the promise to allow for ultrathin channels built of single atomic monolayers in ultimately scaled field-effect transistors (FETs). Due to this small thickness, an enhanced gate control is achieved while at the same time sizable mobilities in the 2D materials can be maintained[1]. In this way, the on-current density of the devices could potentially be increased to up to 1mA/μm by stacking six nanosheets on top of each other, combining p-type and n-type FETs in vertical integration. Even though FETs based on 2D materials hold a lot of promise, numerous challenges still need to be overcome. One of the most serious obstacles is the identification of a suitable gate stack. Over the last years, several insulators have been suggested, including layered insulators like hBN[2], ionic insulators like CaF2[3], amorphous high-k dielectrics like HfO2[4], see Fig.1. In addition, crystalline perovskites like SrTiO3[5] or native oxides like Bi2SeO5[6] have been explored. However, which of these materials provides the best performance is at the moment unclear and needs to be evaluated according to the criteria of scalability (Section 2), the minimization of charge traps (Section 3), and batch-processing compatible deposition technology for double-gated device designs (Section 4). 2.Scalable Gate Stacks High-performance FETs require a high on/off current ratio and steep subthreshold slopes. In order to preserve these characteristics in devices with ultimately scaled channel lengths, the insulator capacitance needs to be higher than 1.5μFcm-2, corresponding to a capacitive equivalent thickness smaller than 1nm. At the same time, if the insulator thickness becomes too small, the gate leakage current often easily exceeds the low-power limit of 0.015 Acm-2, thereby increasing the standby power consumption in the off-state. In fact, the gate leakage currents through thin hBN layers are high, rendering it unsuitable as a gate insulator for scaled FETs, while CaF2, HfO2 or Bi2SeO5 show promise[7]. 3.Minimizing Charge Traps The gate insulator should form a van der Waals interface with the 2D semiconductor, as otherwise, interface traps will degrade the carrier mobility and the sub-threshold slope[8]. Charge traps within the insulators cause limited stability and reliability of 2D FETs, as seen by a large hysteresis in the transfer characteristics or in Bias Temperature Instabilities. As a consequence, the stability can be enhanced if the defect bands in the gate insulator are energetically far away from the conduction and valence band edges[9]. Thus, the number of electrically active charge traps can be minimized by selecting a suitable combination of 2D semiconductor to insulator or by reducing the width of the defect bands by using crystalline insulators. 4.Deposition Technology Gate insulators need to be deposited on top of 2D semiconductors for top gate formation. However, the inert planes of 2D materials inhibit direct nucleation of insulators from the gaseous phase in an atomic layer deposition process. In this context, a promising approach is to use a self-assembled polymer monolayer to nucleate the precursors[4]. Molecular beam epitaxy is an alternative growth approach for gate insulators which offers the advantage of van der Waals epitaxy for layered materials, where the lattice-matching conditions are relaxed[10]. In order to avoid the growth of the insulator on top of the 2D semiconductor altogether the in-situ oxidation of the 2D semiconductor to its native oxide is a promising option, like for Bi2SeO5. 5.Conclusions Even though many novel insulator systems for 2D FETs have been proposed over the last couple of years, it is still unclear which of them best meets the requirements formulated. The most important questions to be addressed in the future will be to identify systems with reproducibly small interface and border trap densities and high thermal stability and to develop suitable batch-processing compatible top gate deposition methods for these material systems. Acknowledgments The authors thank for funding from the European Research Council under grant agreement no.101055379.

Enhanced supercapacitors and LPG sensing performance of reduced graphene oxide/cobalt chromate pigments for energy storage applications

It is imperative that an initial inquiry be conducted as soon as possible since the production of monolayer of carbon atoms (rGO) composites is the root cause of their poor performance in supercapacitor and LPG sensors. Here, an effort is undertaken to construct a cobalt chromate pigments-reduced graphene oxide (CoCr2O4/rGO) by solution combustion method for the supercapacitor and LPG sensor. The proposed method is efficient and easy in terms of its application to the production of CoCr2O4/rGO polycrystalline composite on a wide scale. Within the scope of this work is an investigation into the improved supercapacitor and LPG sensing behaviour of CoCr2O4/rGO polycrystalline composite. We have implemented a simple method that has been identified for mass-producing reduced graphene oxide. The Solution combustion technique was used, and it was successful in achieving this goal for the very first time. X-ray diffraction technique is used analyse crystallinity, phase, and structural investigation. The nature of gas sensing behaviour with a step function of LPG gas at 500 ppb was studied at room temperature for rGO, The CoCr2O4 pigments and 0.5CoCr2O4+0.5rGo polycrystalline composite samples. The gas response is maximum for 0.5CoCr2O4+0.5rGo polycrystalline composite in the order of 97% in compare with the reduced graphene oxide sample which shows the lowest sensitivity in the order of 26% on exposure of liquified petroleum gas (LPG). The recorded response and recovery times of 0.5CoCr2O4+0.5rGo polycrystalline composite is found to be 40 s and 52 s respectively in comparison to the rGO sample about 58 and 74 s respectively. By adding rGo to the material, the cyclic voltammetry (CV) findings demonstrate improved current density and area of CV loop with increased scan rate. In three-electrode reveals the system, a CoCr2O4-rGo material exhibits a specific capacitance of 226 F/g. Thus, the results reveals that rGo is contributing significantly to the enhancement of a supercapacitor's performance of CoCr2O4.

Enhanced dielectric permittivity of novel ternary La2Cu–AgO4 nanocomposites with different ratios of 2-D Borophene nanofiller

Borophene is a monolayer of boron atoms that exhibits notable physical and chemical characteristics, making it the lightest two-dimensional material known to date. Simultaneously, the compositions of silver-copper oxide and lanthanum-copper oxide exhibited unique applications. The present study was motivated by the need to investigate the potential benefits of combining La2Cu–AgO4 ternary nano composition with 2-D Borophene. The successful synthesis of La2Cu–AgO4 nanoparticles and 2-D Borophene has been achieved through simple and cost-effective methods. The La2Cu–AgO4/Borophene composite, with varying weight percentages, has been subjected to various characterization techniques for analysis. The electrical properties of the prepared samples were analyzed. The present study indicates that Borophene has enhanced the dielectric properties of La2Cu–AgO4 nanoparticles by a factor of approximately 2–5. An additional fascinating characteristic of the La2Cu–AgO4/Borophene nanocomposites that were prepared is the presence of a negative Schottky barrier, which exhibits a small value. The incorporation of 2-D Borophene resulted in a reduction of the resistivity of La2Cu–AgO4 by 14–17% compared to its initial value. Moreover, in comparison to the pure La2Cu–AgO4 ternary nanocomposite, the nanocomposite samples of 2-D La2Cu–AgO4 demonstrated reduced activation energy, potential barrier height, and density. The results obtained from the study demonstrate that the material possesses a high dielectric constant value, low resistance, and is lightweight and cost-effective. These properties make it a promising candidate for use in telecommunications and solid-state semiconductor applications, as it can be easily applied.

Quantum Spin Hall Effect in Two-Monolayer-Thick InN/InGaN Coupled Multiple Quantum Wells.

In this study, we present a theoretical study of the quantum spin Hall effect in InN/InGaN coupled multiple quantum wells with the individual well widths equal to two atomic monolayers. We consider triple and quadruple quantum wells in which the In content in the interwell barriers is greater than or equal to the In content in the external barriers. To calculate the electronic subbands in these nanostructures, we use the eight-band k∙p Hamiltonian, assuming that the effective spin-orbit interaction in InN is negative, which represents the worst-case scenario for achieving a two-dimensional topological insulator. For triple quantum wells, we find that when the In contents of the external and interwell barriers are the same and the widths of the internal barriers are equal to two monolayers, a topological insulator with a bulk energy gap of 0.25 meV can appear. Increasing the In content in the interwell barriers leads to a significant increase in the bulk energy gap of the topological insulator, reaching about 0.8 meV. In these structures, the topological insulator can be achieved when the In content in the external barriers is about 0.64, causing relatively low strain in quantum wells and making the epitaxial growth of these structures within the range of current technology. Using the effective 2D Hamiltonian, we study the edge states in strip structures containing topological triple quantum wells. We demonstrate that the opening of the gap in the spectrum of the edge states caused by decreasing the width of the strip has an oscillatory character regardless of whether the pseudospin-mixing elements of the effective Hamiltonian are omitted or taken into account. The strength of the finite size effect in these structures is several times smaller than that in HgTe/HgCdTe and InAs/GaSb/AlSb topological insulators. Therefore, its influence on the quantum spin Hall effect is negligible in strips with a width larger than 150 nm, unless the temperature at which electron transport is measured is less than 1 mK. In the case of quadruple quantum wells, we find the topological insulator phase only when the In content in the interwell barriers is larger than in the external barriers. We show that in these structures, a topological insulator with a bulk energy gap of 0.038 meV can be achieved when the In content in the external barriers is about 0.75. Since this value of the bulk energy gap is very small, quadruple quantum wells are less useful for realizing a measurable quantum spin Hall system, but they are still attractive for achieving a topological phase transition and a nonlocal topological semimetal phase.

Phenomenological phase field modeling of monolayer ferroelectrics FEβ-In2Se3

Recently, a number of two-dimensional van der Waals (vdW) ferroelectrics have been reported, showing the potential to develop various ultra-thin smart devices down to the atomic monolayer limit. In particular, they have been demonstrated to exhibit intriguing polar domain structures. However, phenomenological thermodynamic models of vdW ferroelectrics, which can capture their ferroic domain structure evolution, are still lacking, limiting our further exploration of domain-structure-related applications. In this work, combining first-principles calculations, we construct a phenomenological phase field model for monolayer ferroelectrics, FEβ-In2Se3. Based on the model, one can calculate the phase stability, ferroelectric hysteresis curves, and domain structures of FEβ-In2Se3 under different loading conditions, showing the feasibility of electromechanically driving the rotation of in-plane polarization and manipulation of the domain structures. By including the second-order partial derivative gradient energy term, the model further captures well the antiferroelectric–ferroelastic domain structures of β′-In2Se3 observed in previous experiments. The developed phase field model should help better understand the domain structure evolution behavior in low-dimensional materials and promote further exploration of domain-structure-related applications.

Detection of Paramagnetic Spins with an Ultrathin van der Waals Quantum Sensor.

Detecting magnetic noise from small quantities of paramagnetic spins is a powerful capability for chemical, biochemical, and medical analysis. Quantum sensors based on optically addressable spin defects in bulk semiconductors are typically employed for such purposes, but the 3D crystal structure of the sensor inhibits sensitivity by limiting the proximity of the defects to the target spins. Here we demonstrate the detection of paramagnetic spins using spin defects hosted in hexagonal boron nitride (hBN), a van der Waals material that can be exfoliated into the 2D regime. We first create negatively charged boron vacancy (VB-) defects in a powder of ultrathin hBN nanoflakes (<10 atomic monolayers thick on average) and measure the longitudinal spin relaxation time (T1) of this system. We then decorate the dry hBN nanopowder with paramagnetic Gd3+ ions and observe a clear T1 quenching under ambient conditions, consistent with the added magnetic noise. Finally, we demonstrate the possibility of performing spin measurements, including T1 relaxometry using solution-suspended hBN nanopowder. Our results highlight the potential and versatility of the hBN quantum sensor for a range of sensing applications and make steps toward the realization of a truly 2D, ultrasensitive quantum sensor.