Ferromagnetic Signal Research Articles

Spin dynamics investigation and structural analysis of ambient scalable Sr2+ doped zirconium ferrite nanoparticles synthesized by low temperature auto combustion route

Microwave spin resonance behaviour of Sr2+ doped Zirconium ferrite Zr1-xSrxFe2O4; (0 ≤ x ≥ 0.20) nanoparticles synthesized by auto combustion route has been investigated by electron paramagnetic resonance (EPR) which show a broad ferromagnetic resonance signal with a superimposed hump signal which is attributed to ferrite Fe3+ ions and oxygen vacancies which is in agreement with XRD and XPS. EPR shows low spin concentration and smaller relaxation time for Zr0.80Sr0.20Fe2O4 which can be used for hyperthermia and for use as a MRI contrast agent. EDS and XPS confirms the presence of Zr, Sr, Fe, O, and C and HRTEM images confirm growth along (220) and (311) with an interatomic distance of 0.3327 nm and 0.2622 nm respectively, thus, authenticating the formation of spinel structure in agreement with FTIR studies. The magnetic behaviour (M − H loop) shows high saturation magnetization and higher value of effective magnetocrystalline anisotropy (Keff) for Zr0.80Sr0.20Fe2O4.

Experimental conditions for room temperature ferromagnetism in Fe-doped SnO2 via mechanochemical milling and thermal treatment

Identifying optimal experimental conditions, preferably through a simple and cost-effective method, for the fabrication of oxide-diluted magnetic semiconductors, such as Fe-doped SnO2, holds great significance in the quest for spintronic materials operating at room temperature (RT). While mechanochemical milling is a well-established technique meeting these requirements, its numerous milling variables necessitate careful consideration of restricted experimental conditions. In this study, we present some experimental mechanochemical milling conditions to prepare impurity-free iron-doped tin dioxide nanoparticles exhibiting RT ferromagnetic signal. To achieve this, we investigated the effects of milling time, the choice of the starting Sn reactant, and iron concentration on the purity of Sn1−xFexO2 (x = 0, 0.03, and 0.05) nanopowders obtained through mechanochemical milling followed by thermal treatment. Characterization through XRD, XANES, and EXAFS at the Fe K-edge, RT Raman spectroscopy, 119Sn and 57Fe Mössbauer spectroscopies, and magnetic measurements was conducted. Among the experimental techniques, micro-Raman spectroscopy proved the most effective in detecting the formation of hematite as an impurity phase. Our results indicate that extending the milling time to 12 h, as opposed to 3 h, employing anhydrous SnCl2, instead of SnCl2·2H2O and using the low iron concentration of x = 0.03, results in proper conditions for producing impurity-free samples with a robust RT ferromagnetic signal. The oxidation states for iron and tin ions were determined to be 3+ and 4+, respectively, with both occupying octahedral sites, suggesting iron’s replacement of tin. Our findings propose that both the bound magnetic polaron and RKKY models offer potential explanations for the origin of the ferromagnetic signal observed at room temperature in Sn0.97Fe0.03O2 sample milled for 12 h.

Structural and magnetic studies of the frustrated S = 1 kagome magnet NH4Ni2Mo2O10H3

The strong geometric frustration of the kagome antiferromagnets (KAFMs) can destabilise conventional magnetic order and lead to exotic electronic states, such as the quantum spin-liquid state observed in some S=12 KAFM materials. However, the ground state of S = 1 KAFM systems are less well understood. Spin nematic phases and valence bond solid ground states have been predicted to form but a paucity of experimental realisations restricts understanding. Here, the S = 1 KAFM NH4Ni2Mo2O10H3 is presented, which has the 3-fold symmetry of the kagome lattice but significant site depletion, with ∼64% site occupancy. Frustration and a competition between exchange interactions are evidenced through the suppression of order below the Weiss temperature |θW| and observation of ferromagnetic and antiferromagnetic characteristics in the magnetisation data. A semi spin glass ground state is predicted based on the ac-field frequency dependence of the magnetic transition and ferromagnetic signal.

Manipulation of ferromagnetic ordering in magnetic semiconductor Li<sub>1.05</sub>(Zn<sub>0.925</sub>, Mn<sub>0.075</sub>)As by In doping

Magnetic semiconductors (MSs) that can manipulate both spin degree of freedom and charge degree of freedom have become an important research field in semiconductor spintronics. In recent years, a new series of bulk form MSs, which are iso-structure to the iron-based superconductors were reported. In these new materials, spins and carriers are separately introduced, and can be precisely manipulated. Li(Zn, Mn)As with <i>T</i><sub>C</sub> ~50 K is the first bulk MS with spins and charges separated. The Li(Zn, Mn)As has p-type carriers, which is in contradiction with the theoretical calculation results by Mašek et al., who claimed that doping extra Li will induce n-type carriers. So, it is necessary to study the formation reason of hole carriers in Li(Zn, Mn)As and their effect on ferromagnetic ordering. In this work, a series of Li<sub>1.05</sub>(Zn<sub>0.925–<i>y</i></sub>, Mn<sub>0.075</sub>, In<sub><i>y</i></sub>)As (<i>y</i> = 0, 0.05, 0.075, 0.1) new materials are successfully synthesized by introducing n-type carriers into the p-type bulk MS Li<sub>1.05</sub>(Zn<sub>0.925</sub>, Mn<sub>0.075</sub>)As through (Zn<sup>2+</sup>, In<sup>3+</sup>) substitution. Magnetization measurements reveal that all the samples still maintain a ferromagnetic transition signal similar to MS Li<sub>1.05</sub>(Zn<sub>0.925</sub>, Mn<sub>0.075</sub>)As, and the Curie temperature <i>T</i><sub>C</sub> is obviously suppressed with the increase of In-doping concentration. Clear hysteresis loops demonstrate the ferromagnetic ordering state. The resistivity increases gradually with the increase of In-doping concentration. Our results show that the (Zn<sup>2+</sup>, In<sup>3+</sup>) substitution successfully introduces n-type carriers into Li<sub>1.05</sub>(Zn<sub>0.925</sub>, Mn<sub>0.075</sub>)As, and the original p-type carriers in Li<sub>1.05</sub>(Zn<sub>0.925</sub>, Mn<sub>0.075</sub>)As, which are partial neutralized, resulting in the decrease of p-type carrier concentrations, which obviously suppresses the ferromagnetic ordering of Li(Zn, Mn)As. It reflects the important roles played by carriers in forming ferromagnetic ordering in MS materials. The fabrication of Li<sub>1.05</sub>(Zn<sub>0.925–<i>y</i></sub>, Mn<sub>0.075</sub>, In<sub><i>y</i></sub>)As material gives us a better understanding of the mechanism of ferromagnetic ordering in Li(Zn, Mn)As, and these results will be helpful in searching for more novel magnetic semiconductor materials.

Osobennosti povedeniya linii epr (<i>g </i>≈ 4<i>.</i>3) v magnitnykh nanogranulyarnykh kompozitakh

Films of metal-insulator nanogranular composites MxD100 – x with different composition and percentage of metal and dielectric phases (M = Fe, Co, CoFeB; D = Al2O3, SiO2, LiNbO3; x ≈ 15–70 at %) are investigated by magnetic resonance in a wide range of frequencies (f = 7–37 GHz) and temperatures (T = 4.2–360 K). In addition to the usual ferromagnetic resonance signal from an array of nanogranules, the experimental spectra contain an additional absorption peak, which we associate with the electron paramagnetic resonance (EPR) of Fe and Co ions dispersed in the insulating space between the granules. In contrast to the traditional EPR of Fe and Co ions in weakly doped non-magnetic matrices, the observed peak demonstrates a number of unusual properties, which we explain by the presence of magnetic interactions between ions and granules.

Synthesis and magnetic properties of FeSex/FeTey/FeSezTe1-z nanowires

Low dimensional materials with stable properties have been widely favored by many scientists. In this paper, we present the ferromagnetic hexagonal iron chalcogenide FeSex nanowires that are synthesized by chemical vapor deposition (CVD) method, together with FeTey and FeSezTe1-z nanowires. Notably, these nanowires are coated with as-grown carbon shell, which can naturally prevent the oxidization. The magnetic properties are systematically investigated, and the obvious ferromagnetic signals can be observed in FeSex/FeTey nanowires, while for FeSezTe1-z, the ferromagnetic signal is very weak, replaced by a clear paramagnetic behavior. Additionally, quasi-one-dimensional (Q1D) heterojunctions are achieved, providing unprecedented opportunities in the field of electronic/spintronic devices. Our results offer valuable insights for further exploration of FeSex nanowires and heterojunctions.

Energy dissipation on magic angle twisted bilayer graphene

Traditional Joule dissipation omnipresent in today’s electronic devices is well understood while the energy loss of the strongly interacting electron systems remains largely unexplored. Twisted bilayer graphene (tBLG) is a host to interaction-driven correlated insulating phases, when the relative rotation is close to the magic angle (1.08∘). We report on low-temperature (5K) nanomechanical energy dissipation of tBLG measured by pendulum atomic force microscopy (p-AFM). The ultrasensitive cantilever tip acting as an oscillating gate over the quantum device shows dissipation peaks attributed to different fractional fillings of the flat energy bands. Local detection allows to determine the twist angle and spatially resolved dissipation images showed the existence of hundred-nanometer domains of different doping. Application of magnetic fields provoked strong oscillations of the dissipation signal at 3/4 band filling, identified in analogy to Aharonov-Bohm oscillations, a wavefunction interference present between domains of different doping and a signature of orbital ferromagnetism.

Engineering lattice oxygen defects and polaronic transport in vanadium pentoxide via isovalent phosphorus doping

Oxygen vacancies are equilibrium defects in the vanadium pentoxide system that give rise to polaronic hopping transport via V4+ charge compensating defect. In this paper, we report the tunability of polaron formation, the hopping process, and their magnetic signature by substitution of isovalent (5+) phosphorus ions in the V5+ site. The powder x-ray diffraction data show a monotonous shift in lattice parameters with progressive P-doping, confirming the presence of a substitutional dopant. The polaron hopping energy reduced from 0.307 to 0.290 eV depicting a lower defect concentration in P-doping in V2O5. At low temperatures, it is found to obey the Efros–Shklovskii variable range hopping mechanism. The estimated hopping range increased to 1.6 ± 0.1 nm in doped V2O5 in contrast to ∼1.3 nm in the undoped one. The electron spin resonance measurements show a diminishing broad ferromagnetic signal and rising paramagnetic signal (g = 1.97) with progressive P-doping depicting predominant isolated electronic spins in the doped sample. The same is corroborated in room temperature M–H with a distinct hysteresis that diminishes with P-doping and a rise of a paramagnetic slope. Moreover, the reduced oxygen defects and lower V4+ relative occupancy together with fermi level fall toward intrinsic position are substantiated by photoelectron emission studies.

Dzyaloshinsky–Moriya Interaction Induced Anomalous g Behavior of Sr2IrO4 Probed by Electron Spin Resonance

Among the 5d transition metal iridates, Sr2IrO4, which has a layered chalcogenide structure, has received much attention due to its strong spin–orbit coupling (SOC), which produces Mott insulating states and anomalous physical behaviors. In this paper, the microscopic magnetism of Sr2IrO4 is studied with electron spin resonance (ESR) measurements. The Lande factor g of the ferromagnetic resonance signal of Sr2IrO4 shows anomalous behavior compared to typical ferromagnets. It gradually decreases, and the corresponding resonance field Hr increases, with decreasing temperature. The various physical parameters. including the saturated magnetic field Hs derived from M-H, Hr, ΔHpp, the g factor and the intensity I extracted from ESR spectra, are analyzed in detail. Eventually, it is revealed that the anomalous behavior of the g-factor is induced by in-plane Dzyaloshinsky–Moriya interaction (DMI) rather than the SOC effect.

Emergent ferromagnetism with superconductivity in Fe(Te,Se) van der Waals Josephson junctions

Ferromagnetism and superconductivity are two key ingredients for topological superconductors, which can serve as building blocks of fault-tolerant quantum computers. Adversely, ferromagnetism and superconductivity are typically also two hostile orderings competing to align spins in different configurations, and thus making the material design and experimental implementation extremely challenging. A single material platform with concurrent ferromagnetism and superconductivity is actively pursued. In this paper, we fabricate van der Waals Josephson junctions made with iron-based superconductor Fe(Te,Se), and report the global device-level transport signatures of interfacial ferromagnetism emerging with superconducting states for the first time. Magnetic hysteresis in the junction resistance is observed only below the superconducting critical temperature, suggesting an inherent correlation between ferromagnetic and superconducting order parameters. The 0-π phase mixing in the Fraunhofer patterns pinpoints the ferromagnetism on the junction interface. More importantly, a stochastic field-free superconducting diode effect was observed in Josephson junction devices, with a significant diode efficiency up to 10%, which unambiguously confirms the spontaneous time-reversal symmetry breaking. Our work demonstrates a new way to search for topological superconductivity in iron-based superconductors for future high Tc fault-tolerant qubit implementations from a device perspective.

The size dependence and defect induced room temperature ferromagnetism of ZnO and Zn 1-x-y AlxZyO (Z=Mg/Ni) nanocomposites

In the current research, Al-Mg-ZnO and Al-Ni-ZnO nanocomposites were synthesized by using simple soft chemical route. Prepared nanocomposites of Al-Mg-ZnO and Al-Ni-ZnO with capsule shape distributed magnetite nanostructured were carried out under the calcinated at 120 C for 12 h in furnace. The structural morphology and characterization analysis of as prepared nanocomposites was analyzed by XRD, UV–vis. FTIR, PL, TEM, VSM studies. XRD analysis confirmed the highly pure crystallized cubic phases. The XRD peaks show that the crystalline sizes are of the order of 22 nm, 19 nm, and 11nm. Magnetic property of the prepared nanocomposites was discussed in room temperature using VSM measurement. In spite of a number of researchers reporting the effect of codoping ZnO nanoparticles (NPs) with two different metals was modify the properties of the entire system such as enrich in room-temperature ferromagnetism. In this research we tried to by experimentally observed the magnetic properties of a series of soft chemical synthesized Zn1-x-yAlxZyO (Z=Mg/Ni) nanocomposites. Interestingly, it was found that in comparison to un-doped ZnO NPs and co-doped with two different metals. The ferromagnetic signal changes in a co-doped system in which one of the Mg/Ni ions increases the concentration of defects mechanism when Mg/Ni ions exhibited only one oxidation state. The potential role of charge transfer ferromagnetism is involving Mg2+ and Ni2+ ions substituted into ZnO lattice, The origin of magnetism in the nanocomposites is due to exchange interaction between local spin polarized electrons and the conduction electrons. The potential role of charge transfer ferromagnetism involving mixed valence ions and effects defect mechanism was used to explain the room temperature ferromagnetism.

MnCaTa2O7-A Magnetically Ordered Polar Phase Prepared via Cation Exchange.

Reaction between the pseudo-Ruddlesden-Popper phase Li2CaTa2O7 and MnCl2 at 375 °C yields MnCaTa2O7, a paramagnetic polar phase (space group P21nm), which adopts an a-b-c+/b-a-c+ distorted, layered perovskite structure. Magnetization and neutron diffraction data show that MnCaTa2O7 adopts an antiferromagnetically ordered state below TN = 56 K and exhibits large lattice parameter anomalies and a transient increase in its polar distortion mode at TA = 50 K. However, in contrast to the related phase MnSrTa2O7, MnCaTa2O7 shows no strong signature of weak ferromagnetism and thus shows no signs of magnetoelectric coupling. The differences in physical behavior between the two MnATa2O7 phases appear to be related to their differing Mn cation-order and differing TaO6 tilting schemes and demonstrate that even subtle changes to these orderings can have large effects on the distortion-mode couplings, which drive complex behavior of this class of "hybrid improper" ferroelectric material.

Effect of Stereochemically Active Electron Lone Pairs on Magnetic Ordering in Trivanadates.

Stereoactive electron lone pairs derived from filled 5/6s2 states of p-block cations are an intriguing electronic and geometric structure motif that have been exploited for diverse applications such as thermoelectrics, thermochromics, photocatalysis, and nonlinear optics. Layered trivanadates are dynamic intercalation hosts, where the insertion of cations can be used to tune electron correlation, charge localization, and magnetic ordering. However, the interaction of 5/6s2 stereoactive electron lone pairs with layered trivanadates remains unexplored. In this study, we contrast s- and p-block trivanadates and map off-centering in the coordination environment and reduction in symmetry arising from the stereochemical activity of lone pair cations to the emergence of filled antibonding lone-pair 6s2-O 2p hybridized states. The former is studied by high-resolution single-crystal X-ray diffraction studies of TlV3O8 and isostructural RbV3O8 to probe distinct differences in Tl and Rb coordination environments and the resulting modulation of V-V interactions in V3O8 slabs. The latter has been probed by variable-energy hard X-ray photoelectron spectroscopy (HAXPES) measurements, which manifest orbital-specific contributions from bonding and antibonding interactions of stereoactive Tl 6s2 electron lone pairs in TlV3O8. The spectroscopic assignment of valence band states to stereoactive lone pairs is further corroborated by first-principles electronic structure calculations, crystal orbital Hamilton population analyses, and electron localization function maps. The presence of the Tl 6s2 electron lone pair in TlV3O8 brings about the off-centering of Tl+ cations, which leads to anisotropy in Tl-O bonds. The off-centering of Tl ions weakens V-O bonds in one direction, which subsequently strengthens directional V-V coupling. Magnetic measurements reveal ferromagnetic signatures for both RbV3O8 and TlV3O8. However, the differences in V···V interactions significantly affect the energy balance of the superexchange interactions, resulting in an ordering temperature of 140 K for TlV3O8 as compared to 125 K for RbV3O8. The results demonstrate the distinctive effects of stereochemically active lone pairs in modifying electronic structure near the Fermi level and for mediating superexchange interactions.

Magnetic field enabled spin-state reconfiguration for highly sensitive paper-based photoelectrochemical bioanalysis

Efficient carrier separation plays an utterly pivotal role in enhancing the sensitivity of photoelectrochemical (PEC) analysis. Here we report a concise yet powerful strategy of electron spin polarization induced by magnetic stimulation, to effectively modulate the efficiency of charge separation in a paper-based PEC (μ-PEC) sensing system. The electronic configuration of the sulfur-defected CdIn2S4/FeOOH photoactive matrix and ferromagnetic ZnFe2O4 signal label were regulated via the electron parallel alignment along with spin state flip and reconstruction at particular active sites under external magnetic field, significantly facilitating the separation of photoinduced carriers. As a proof-of-concept application, the magnetic-triggerable spin-state reconfiguration coupled with enzymatic catalytic precipitation reaction was developed for detection of chlorpyrifos with a wide linear range of 10-2.5-106 ng mL−1 and low detection limit of 0.67 pg mL−1. This work provides the basis for understanding the role of magnetic stimulus in tailoring charge separation and constructing a universal strategy for high performance μ-PEC bioanalysis.

Surface-disorder and cationic-site defect-induced ferromagnetism and correlated Raman vibrational modes in Sn0.9 In0.1O2 nanocrystalline thin-films

Exploration of magnetism in otherwise nonmagnetic wide-band oxides through defect-engineering has been become a new challenge to achieve the goal of room-temperature ferromagnetic semiconductor for potential applications in spintronics. In this backdrop, we report surface-disorder and cationic-site defect-induced FM in series of Sn0.9In0.1O2 nanocrystalline thin films prepared using pulsed laser deposition different Argon (Ar) pressure. With the increase of deposition pressure, surface morphology of Sn0.9In0.1O2 nanocrystalline thin-films changes as nanoclusters, nanofibres, nanoflakes and nanowires respectively, crystallite size decreases and surface disorder increases gradually. Raman, X-ray photoelectron and Photoluminescence spectroscopic analysis confirm the formation tin-vacancy (VSn) and associated combinational defects that significantly increase the ferromagnetic signal in In-doped SnO2 thin-films. The substitution of trivalent In3+ in Sn site also cause serious lattice distortion which transform the Raman inactive modes A2g and Eu modes into Raman active modes and thus appeared at 574 cm−1 and 354 cm−1 respectively. The nanowires of Sn0.9In0.1O2 are found to possess highest concentration of VSn defects and therefore it exhibits strongest ferromagnetic moment (MS) ∼ 11.1 emu/cm3 and highest Curie temperature (TC) ∼ 572 K. The gradual decrease in carrier concentration with the increasing deposition pressure suggests stabilization of hole-mediated VSn-induced room temperature FM in series of In-doped SnO2 nanocrystalline thin-films.

Investigating the magnetic properties of rGO, and rGO-ZnO nanocomposite

In the present work, magnetic properties of the graphene oxide (GO), reduced graphene oxide (rGO), rGO-ZnO hybrid (RGZ) nanocomposite and ZnO nanorods have been investigated. A simple hydrolysis method is used to synthesize (RGZ) nanocomposite and ZnO nanorods. The structural and the morphological studies are performed using XRD, TEM, FTIR, TGA and FESEM. Magnetic properties of the samples have been investigated through SQUID magnetometer. The as synthesized GO, rGO samples show diamagnetic behavior with weak ferromagnetic component at room temperature (RT) while at low temperatures (10 K) these samples exhibit paramagnetic behavior with small ferromagnetic signature. As synthesized ZnO nanorods exhibit weak ferromagnetism at RT. The RGZ nanocomposite exhibits weak ferromagnetic behavior at RT and the magnetization value is found greater than that of ZnO. Moreover, RGZ nanocomposite shows higher value of magnetization than GO, rGO and pure ZnO samples at low temperatures. Further, we have investigated the temperature dependent magnetization (M−T) in zero field cooled (ZFC) and field cooled (FC) conditions for ZnO nanorods, GO, rGO and rGO-ZnO samples at 100 Oe applied magnetic field. The possible mechanisms for magnetic behavior of rGO-ZnO composite are discussed and described in this manuscript.

Magnetic Proximity Effect in LaMnO3-LaFeO3 Bilayer

Here, we report the magnetic properties of LaMnO3, LaFeO3 thin films and their heterostructures, fabricated using Pulse laser deposition technique (PLD) on SrTiO3(001) substrate. The crystal structure, surface morphology signifies the phase pure epitaxial growth of LaMnO3 and LaFeO3 films and their heterostructure. The magnetic characteristics of individual LaMnO3 and LaFeO3 films along with their heterostructures were studied to explore the proximity effect of the different antiferromagnets. We demonstrate that LaMnO3 thin film shows ferromagnetic signal with inconspicuous Tc. The ferromagnetic signal is stronger in case of LaMnO3 grown on buffered LaFeO3 and LaFeO3 on top of LaMnO3. The change of Tc is analyzed in heterostructures as compared to the bare LaMnO3. Additionally, our study illustrates the variation of anisotropic energy and spin flop coupling between the interface with alternate growth sequence of heterojunctions.

산화철 나노입자의 결합 모양에 따른 강자성 공명 신호 분석

산화철 나노입자는 고온 열분해법을 이용하여 제조하였으며, 2차원 나노입자 박막 재료의 FMR 신호를 측정하여 산화철 나노입자의 유효 포화자화 MSUBeff/SUB = 202 emu/cc와 g-factor = 2.12를 얻었다. 나노입자를 포함하고 있는 최종 반응 원액의 강자성 공명 신호를 분석하기 위하여 자성 재료의 모양에 따른 Kittel의 강자성 공명 조건을 활용하였다. 반응 원액의 강자성 공명신호는 두 개의 신호로 분리되어 나타났다. 하나는 초상자성에 의한 신호였고, 다른 하나는 1차원 체인(chain) 구조를 갖는 나노입자들에 의한 신호임을 알 수 있었다.

Effect of annealing temperature on structural, optical and magnetic properties of Cd1-xMnxZnO2 nanocomposites: An investigation for ferromagnetic

The structural, optical, and magnetic qualities of Cd1-xMnxZnO2 nanocomposites with (0.00 ≤ x ≤ 1.00) are investigated and the paramagnetic ferromagnetic transition is explained. Two series (effect of annealing and composition) were synthesized using the hydrothermal method and then annealed for 3 h at annealing temperatures (Tann) of 400 °C or 600 °C. It is found that an increase in either x or Tann correlates with significant change in unit cell volume (V), crystallite size (Dhkl), Debye temperature (θD) and energy gap (Eg). Further, the samples at x = 0.60 show a sudden change or inflection point in the behavior of these parameters is detected. Furthermore, the values of Eg and Dhkl for the x = 0.60 sample are independent of the chosen Tann. The weight percent of oxygen increased as x increased, as well as it was higher at 600 °C than at 400 °C. The value of Dhkl at x = 0.40 was increased by increasing Tann from 20.7 nm to 26.3 nm. Surprisingly, both series of samples exhibit weak paramagnetic properties as x increases to 0.40. However, increasing x to 0.60 yields a strong ferromagnetic signature for both series as well as unusual unsaturated magnetizations of 4.20 and 1.25 emu/g. However, with a larger further than of x above 0.60, the behavior returns to a strong paramagnetic behavior, but with a small percentage of residual hysteresis. These novel outcomes open the way for a possible mechanism for room temperature ferromagnetic (RTFM) and strongly recommend the use of Cd1-xMnxZnO2 nanocomposites, for magnetic imaging, and spintronic devices.

Controlling the Magneto-Optical Response in Ultrathin Films of EuO1-x via Interface Engineering with Ferroelectric BaTi2O5.

Utilizing pulsed laser deposition, a film of EuO1-x was deposited onto a Si(001) substrate with MgO buffer and compared to the same heterostructure with an additional BaTi2O5 thin film on top of the EuO1-x surface. X-ray diffraction (XRD) indicates the films crystallize into a preferred EuO(111) orientation; it also reveals the clear presence of EuSi2, which suggests Si or Eu diffuses across the MgO buffer layer. EuO1-x films exhibit a ferromagnetic (FM) signature and temperature-dependent exchange bias, indicated by MOKE measurements, suggesting the presence of a magnetic order well above the EuO Curie temperature with possible origins in charge carrier density near the interface. In comparison, an antiferromagnetic character persists well above the EuO Curie temperature of 69 K and the enhanced Curie temperature of 150 K for BaTi2O5 films grown on the EuO1-x films. The antiferromagnetic behavior is not seen in thicker EuO1-x thin films when integrated with other ferroelectric (FE) phases of the BaO-TiO2 system, suggesting an origin in the perturbed charge population at the BaTi2O5/EuO1-x interface.