Glass Behavior Research Articles

A brief review of spin glass magnetometry techniques

Spin glasses are inherently dynamical. Taken properly, measurements of these materials can capture their dynamics and provide a wealth of insight into the physics of the spin glass state. In this methods review, two magnetometry methods are directly compared–ac and dc. Because these measurements are taken differently, the resulting data of each method will contain different information about spin glass behavior. This review will specifically focus on how the out-of-equilibrium effects of aging, rejuvenation, and memory manifest in each of these techniques, and how to construct protocols to measure these effects. We then describe the physical significance of each type of measurement and how to interpret their results. Finally, we explicitly detail which applications are most appropriate for which method. This will help the reader select the most helpful technique to carry out their own future experiments.

Understanding of leaching, immobilization and oxidation behaviors of chromium in Cr2O3-doped aluminosilicate glasses

Vitrification is an efficient and green approach to prepare cement supplementary material using hazardous solid waste. However, research on the safety and toxicity of chromium-containing glass remains limited. In this study, chromium leaching, immobilization and oxidation behaviors in calcium aluminosilicate glass with various SiO2:Al2O3 and Cr2O3 are studied. The glass system with the lowest Cr leaching amount was obtained at the SiO2:Al2O3 ratios of 3:4, with 50.87 % chromium distribute in glass and 49.13% in Al2O3 phases, enhancing the chromium immobilization capacity. Double immobilization mechanism was proposed, which involves the solid solution of Cr in the glass network structure and chemical consolidation in the Al2O3 phase. The dissolution and erosion of minerals is the main reason of chromium leaching. A higher degree of polymerization glass exhibits stronger corrosion resistance and lower chromium leaching amounts, contributing to the stable connection of [SiO4] tetrahedra in the glass network structure. The initial pH value of the extractant had little effect on the chromium leaching amount. The chemical composition of glass mainly affects the pH of final leaching solution. The glass with SiO2:Al2O3 ratios of 3:4 shows the safest chemical composition, the final leaching solution exhibits acidity, which inhibits the oxidation chromium.

Pore defect and corrosion behavior of HVAF-sprayed Co21Fe14Ni8Cr16Mo16C15B10 high entropy metallic glass coatings

Pore defect is a primary bottleneck limiting corrosion resistance of the coatings. The relationship between porosity and corrosion behaviors of HVAF-sprayed Co21Fe14Ni8Cr16Mo16C15B10 high entropy metallic glass (HE-MG) coatings was investigated by 3D XRT, XPS, SKPFM and SVET techniques. The potential difference between pores and surrounding regions expedites corrosion tendency. The corrosion current density of the coating and concentration of defects in passivation film increase as a function of porosity, thereby degrading corrosion resistance. The lowest porosity coating displays exceptional anti-corrosion due to compact films enriched with Cr2O3 and Mo4+ oxides. These findings provide valuable insights for designing corrosion-resistance coatings.

Influence of the substitution of CaO by SrO on the structure, degradation and in vitro apatite formation of sol–gel derived SiO2–CaO–SrO–P2O5system bioactive glasses

The present study investigates the influence of the substitution of CaO by SrO on the structure, degradation and in vitro apatite formation of sol–gel-derived bioactive glasses with composition of 58SiO2–(38-x)CaO–xSrO–4P2O5, where x varies between 0 and 10 mol.%. The IV-type nitrogen adsorption/desorption isotherms and pore size values (ranging from 5.41 to 12.56 nm) confirmed the mesoporous structure of the synthesized glasses. The detailed structural analysis was carried out by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). As network modifiers, the addition of Ca and Sr oxides disrupted the bonds of bridging oxygens (BOs) and resulted in the formation of non-bridging oxygens (NBOs), where the substitution of Ca with Sr led to an increase in Q1 units and a decrease in Q3 units. The effects of the addition of Sr on sample degradation and apatite formation were assessed using an assay in tris-(hydroxymethyl)-aminomethane and hydrochloric acid (Tris–HCl) and simulated body fluid (SBF). The results demonstrated that the substitution of CaO by SrO in the CaO–SiO2–P2O5 bioglass system altered the glass structure, resulting in reduced sample degradation and delayed apatite formation. This suggests that the incorporation of Sr into bioactive glasses may serve as a promising strategy to regulate the structure, dissolution behavior and apatite formation of silicate-based glasses, particularly concerning their long-term applications within the human body.

Crystallization behavior of fluorozirconate glasses as monitored by 35Cl NMR

The 35Cl nuclear magnetic resonance (NMR) spectroscopy was first used to study the crystallization of erbium-doped fluorochlorozirconate glass in the ZrF4–BaF2–BaCl2–LaF3–AlF3–NaF system. It has been shown that crystallization results in the increasing homogeneity of electronic structure on chlorine atoms and a narrowing of the NMR line. The glass being crystallized, erbium cations are displaced into the fluoride phase.

Cluster spin glass behaviour of Co2+−Al3+ layered double hydroxides

Frequency-dependent magnetic behaviour of cobalt-aluminium layered double hydroxides (LDH) with the Co/Al ratio of 2 and 3, was studied between 2 and 300 K. It was found from analysis of the temperature-dependent ac magnetic susceptibility that these LDH exhibit a magnetic cluster spin glass behaviour regardless of their basal spacing value and the Co/Al ratio as evidenced by EA/kBT0 > 1 relation obtained using Vogel-Fulcher law. The obtained values of Mydosh parameters in the range of 0.017–0.052 suggest that some of these materials are not far from the canonical spin glasses, implying a rather small size of the magnetic clusters.

Bessel Beam Femtosecond Laser Interaction with Fused Silica Before and After Chemical Etching: Comparison of Single Pulse, MHz-Burst, and GHz-Burst.

We investigate the elongated modifications resulting from a Bessel beam-shaped femtosecond laser in fused silica under three different operation modes, i.e., the single-pulse, MHz-burst, and GHz-burst regimes. The single-pulse and MHz-burst regimes show rather similar behavior in glass, featuring elongated and slightly tapered modifications. Subsequent etching with Potassium Hydroxide exhibits an etching rate and selectivity of up to 606 μm/h and 2103:1 in single-pulse operation and up to 322 μm/h and 2230:1 in the MHz-burst regime, respectively. Interestingly, in the GHz-burst mode, modification by a single burst of 50 pulses forms a taper-free hole without any etching. This constitutes a significant result paving the way for chemical-free, on-the-fly drilling of high aspect-ratio holes in glass.

Pressure-induced structural variations and mechanical behavior of silicate glasses: Role of aluminum and sodium

This study investigates the effects of pressure-induced densification on the structural and mechanical properties of albite-like (12.5 % Na2O·12.5 % Al2O3·75 % SiO2) and sodium silicate (12.5 % Na2O·87.5 % SiO2) glasses using Molecular Dynamics simulations. Densification increased the coordination numbers of Al and Na, facilitated Al-O-Al clustering and formation of three-bridging oxygens, reduced T-O-T angles, and packed sodium ions in albite glass. Sodium silicate glass exhibited densification primarily through increased Na coordination, reduction of Si-O-Si angle and reduced Na-Na distances. Elastic modulus calculations revealed increased stiffness with densification due to enhanced atomic packing and glass reticulation. Uniaxial tensile tests showed densified glasses had higher ductility and strength than undensified counterparts, highlighting the positive effects of pressure-induced structural rearrangements. Hydrostatic compression tests demonstrated reversible densification under varying pressure loads, with pre-treatment conditions significantly affecting residual densification.

Tribological behaviors of Zr-based bulk metallic glass against Si3N4 ceramic under linear reciprocating sliding

Tribological properties of bulk metallic glasses (BMGs) deeply affect their performances in potential applications, however, the main wear mechanisms remain partially understood, for the vastly varying contact conditions in friction. This work systematically reports tribological behaviors of Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG against Si3N4 ceramic during linear reciprocating sliding at different normal load (1–12 N) and reciprocating frequency (1–12 Hz). The time-dependent coefficient of friction (COF) indicates a prominent “running-in” stage during wear tests, which lengthens upon increased normal load while reduces at increased reciprocating frequency. Observation on worn surfaces indicates that the wear mechanism during “running-in” is mainly adhesive wear while in the stable stage is oxidative wear and adhesive wear. Intriguingly, high wear rate generally relates to adhesive wear and low wear rate relates to oxidative wear, while high COF relates to oxidative wear and low COF relates to adhesive wear. These results would help to understand the friction and wear of BMGs.

Unveiling the boson peaks in amorphous phase-change materials

The Boson peak is a universal phenomenon in amorphous solids. It can be observed as an anomalous contribution to the low-temperature heat capacity over the Debye model. Amorphous phase-change materials (PCMs) such as Ge-Sb-Te are a family of poor glass formers with fast crystallization kinetics, being of interest for phase-change memory applications. So far, whether Boson peaks exist in PCMs is unknown and, if they do, their relevance to PCM properties is unclear. Here, we investigate the thermodynamic properties of the pseudo-binary compositions on the tie-line between Ge15Te85and Ge15Sb85from a few Kelvins to the liquidus temperatures. Our results demonstrate the evidence of the pronounced Boson peaks in heat capacity below 10 K in the amorphous phase of all compositions. By fitting the data using the Debye model combined with a modification of the Einstein model, we can extract the characteristic parameters of the Boson peaks and attribute their origin to the excess vibrational modes of dynamic defects in the amorphous solids. We find that these parameters correlate almost linearly with the Sb-content of the alloys, despite the nonmonotonic behaviors in glass forming abilities and thermal stabilities. In a broader context, we show that the correlations of the characteristic parameters of the Boson peaks with Tg and kinetic fragility, vary according to the type of bonding. Specifically, metallic glasses and conventional covalent glasses exhibit distinct patterns of dependence, whereas PCMs manifest characteristics that lie in between. A deeper understanding of the Boson peaks in PCMs holds the promise to enable predictions of material properties at higher temperatures based on features observed in low-temperature heat capacity.

Advanced Monte Carlo method for simulating glass alteration: Application to aluminoborosilicate glasses

AbstractUnderstanding the alteration mechanisms of nuclear glasses is paramount for safety assessment of deep geological disposal of nuclear waste. This endeavor poses significant challenges due to the experimental limitations in observing atomic‐scale mechanisms, which are essential for developing macroscopic alteration models. Consequently, a novel Monte Carlo approach has been developed to simulate the alteration process of simplified nuclear glasses at the atomic level. This approach employs a dual lattice to represent both the solid material and the solution, thereby facilitating the incorporation of diffusion and hydrolysis–recondensation mechanisms. Preliminary findings underscore the critical influence of alteration conditions on glass behavior and elucidate the interplay between rate of hydrolysis at the gel–solution interface and the morphology of the outer layer formed within the gel. Intense hydrolysis promotes the formation of a porous, low‐density layer, whereas slower hydrolysis fosters the development of a dense, cross‐linked layer.

Tunable rejuvenation behavior of Zr55Cu35Al10 metallic glass at the atomic scale during recovery annealing and pressure treatment

In this study, molecular dynamics (MD) simulations were employed to investigate atomic structure characteristics of Zr55Cu35Al10 metallic glasses under various annealing temperature and pressure. Following the initial formation of amorphous, the samples annealed at temperatures ranging from 800 K to 1100 K exhibited a transition from an aged state to a rejuvenated state during the subsequent heat treatment stage. In the third stage of heat treatment, increasing the pressure in samples from 0 to 50 GPa significantly enhanced the degree of rejuvenation compared to raising the temperature. Additionally, applying pressure dramatically enhanced the short-range order in the metallic glass system, altered the proportion of icosahedral cluster types, and contributed to a transformation of Voronoi polyhedrons (VPs) from low local five-fold symmetry to high local five-fold symmetry. Notably, the <0,0,12,0> VP, which represents high local five-fold symmetry, reached a peak proportion of 12.5 %, thereby strengthening the amorphous forming ability.

The magnetic characteristics of spinel-type MnCo2O4 at low temperatures

We report the magnetic properties of spinel oxide MnCo2O4 at low temperatures which is prepared through the sol-gel reaction process. The XPS results suggest that Mn3+ atoms exist in the octahedral sublattice originally occupied by Co3+ atoms. Afterwards, the AC susceptibility was measured at various frequencies, confirming a spin glass behavior at low temperatures. Additionally, analysis of the hysteresis loops revealed the presence of the exchange bias effect in our sample. The coexistence of spin glass behavior and the exchange bias effect in MnCo2O4 is attributed to the competition between ferromagnetic and antiferromagnetic interaction. The disorders of magnetic atoms in the lattice will also provide synergy for these magnetic behaviors.

On the kinetics of structural evolution in metallic glasses

The classic phenomenological models fail to describe the physical landscape of creep deformation for amorphous solids. In this paper, creep behavior of typical metallic glasses with chemical compositions La62Al14Ag2.34Ni10.83Co10.83, Pd20Pt20Cu20Ni20P20 and Cu46Zr39Hf8Al7 were studied. Instead, we attempt to use a modified hierarchically correlated model informed by physics to realize the creep behaviors of metallic glasses. The anelastic deformation of creep is categorized into two distinct components, i.e., the highly correlated deformation unit sensitive to annealing and the low correlated unit associated with diffusion relaxation. The correlated component diminishes with structural aging. The validity of the model is verified by these findings, and the derived parameters provide insights into the structural and kinetic characteristics of metallic glasses. Decreased characteristic times and contrasting correlation factors indicate homogeneous structure and lower energy states. Moreover, a qualitative evaluation of the relative strengths of the dual deformation mechanisms during creep enables the characterization of β relaxation forms, shedding light on the intrinsic attributes of different types of metallic glasses. This methodology additionally facilitates the detection of structural aging and rejuvenation phenomena.

Unlocking high photosensitivity direct laser writing and observing atomic clustering in glass

The direct laser writing (DLW) of photoluminescent metal clusters is inspiring intensive research in functional glasses. However, understanding the influence of the host structure on cluster formation and visualizing DLW-induced clusters at the atomic scale remains challenging. In this work, we develop a highly photosensitive fluorophosphate glass through fluorine incorporation. The addition of fluorine establishes a conducive environment for Ag+ ions before DLW and enhances the availability of reducing agents and diffusion pathways during DLW. These advantages facilitate the formation of Ag clusters under low-energy single-pulsed DLW. Increasing laser energy results in a combination of Ag clusters and glasses defect, forming a dot + ring photoluminescent pattern. Atom probe tomography (APT), a technique capable of mapping the elemental spatial distribution and identifying clustering, is employed to gain more information on laser-induced clusters. Comparison of APT results between samples without and with DLW reveals the formation of Ag clusters after laser writing. The design concept and characterization enrich the understanding of Ag cluster behavior in glasses. This knowledge opens the possibility of rational design of clusters confined in glasses and inspires their synthesis for various applications.

Unique Energy‐Storage Behavior Driven by High Entropy in Metallic Glasses

AbstractThe rejuvenation or energy‐storage behavior in metallic glasses (MGs) has been extensively explored for its theoretical and practical significance. However, very limited research focuses on the rejuvenation of high entropy metallic glasses (HEMGs), leaving uncertainties about how configurational entropy influences this process. In this study, cryogenic temperature cycling (CTC) is utilized to unlock the rejuvenation potential of a series of La‐based MGs with different entropy values. Comparative analysis of these MGs reveals that increased entropy boosts the maximum rejuvenation degree from 37% to 65% and widens the range of energy states where rejuvenation occurs. The changed rejuvenation behavior induced by entropy increase, which has never been reported other studies, are related to glass's structures, fragility and coupling degree between β and α relaxations. Besides, a new rejuvenation mechanism is revealed in HEMGs, which differs significantly from unrestricted growth and interconnection of flow units observed in most MGs. The atomic motion in HEMGs is confined within the icosahedral backbone network during CTC. Surprisingly, this local motion can propagate through strong interactions between adjacent atoms, facilitating the activation of α relaxation. These discoveries offer novel approaches to tune energy‐storage behavior of MGs by modulating icosahedral network structures through entropy control.

Nanoindentation-induced serrated flow behavior and deformation mechanism in metallic glass: A combined experiments and molecular dynamics simulation

In this study, the deformation behaviors of bulk metallic glass (BMG) during the nanoindentation are presented via the experiments and molecular dynamics (MD). The relationship between shear transformation zone (STZ) formation and serrated flow dynamics are developed to explain the deformation characterization evolution of BMG. It is found that as the peak load increases, the hardness and elastic modulus significantly decrease. Creep behavior at room temperature was also revealed by analyzing the creep displacement curve and the stress index under different peak loads.The accumulation of free volume during the deformation process promotes more uniform creep deformation. Furthermore, the serrated flow behaviors were analyzed innovatively using the shear stress drops further statistically. At lower loads, the occurrence of serrated retention is due to energy exceeding the potential barrier required for flow unit activation, ultimately released in the form of kinetic energy. At higher loads, the transition from intermittent curve to smooth curve exhibits a typical self-organized critical (SOC) state dynamic characteristics, and ISE phenomenon is also observed. The results also suggested that the shear deformation of the spherical indenter is more pronounced, with the shear band forming at a 45° angle to the direction of the downward pressure. And based on the Cooperative shear model (CSM) theory, the STZ size was estimated and verify that the increment of STZ makes it easier to generate stronger plastic strain to dissipate STZ, ultimately leading to complete plastic deformation. Combining five fold symmetry and gradient atoms, the majority of atoms with five fold symmetry (LFFS>0.5) have stronger resistance to plastic deformation when the load rate is low.

Structural, morphological, and magnetic characterizations of (Fe0.25Mn0.75)2O3 nanocrystals: A comprehensive stoichiometric determination

This report aims to investigate in depth FeMnO3, a material of interest due to its fascinating magnetic and multiferroic properties and its many applications in fields including lithium-ion batteries, microwave devices, and catalysis. However, understanding the precise stoichiometry of the material is crucial for a better comprehension of its physical properties. A cheap, simple, and repeatable sol-gel process was used to fabricate the FeMnO3 nanocrystals. Comprehensive multi-technique characterization of the as-fabricated FeMnO3 indicates that the main phase (94 wt%) is Fe0.5Mn1.5O3, although hematite appears as the minority phase (6 wt%). Magnetic characterization shows core-shell spin-glass like behavior, as well as paramagnetic-ferrimagnetic transitions and a Griffiths phase regime. EPR measurements revealed a strong and broad resonance line across the temperature range of 4.3 K–300 K, primarily influenced by the majority phase. The g-value decreases monotonically from 2.93 at 50 K to 2.18 at 300 K. There is a notable change in the resonance field and linewidth between 40 and 50 K, attributed to surface spin glass behavior. The EPR data below 50 K are in line with the core-shell model of (Fe0.25Mn0.75)2O3 nanoparticles. Below 50 K, the shell's spin system undergoes a transition from paramagnetic to spin-glass-like, with a critical temperature around 43 K. Above 50 K, the superparamagnetic minority phase significantly affects the temperature dependence of the resonance linewidth. These results hold particular importance as they advance our understanding of the intricate magnetic interactions present in FeMnO3. For the best possible use of this material platform in new technologies, such insights are essential.

Impact of Eu3⁺ on the self-crystallization of CsPbBr1.5Cl1.5 in glass-ceramics for precision temperature sensing applications

All-inorganic perovskite QDs, such as CsPbX3(X = Cl, Br, I), have garnered significant attention in the field of optoelectronics as emerging photonic materials. Rare-earth (RE) doping is an effective strategy for enhancing the optical properties of CsPbX3 perovskite quantum dot glasses. Therefore, investigating the crystallization behavior of rare-earth ion-doped CsPbX3 glass and the energy transfer mechanisms between rare-earth ions and CsPbX3 is crucial for advancing the development of rare-earth-doped perovskite glass materials. The paper systematically introduces the preparation methods, structural characteristics, and applications of CsPbBr1.5Cl1.5 QDs in optoelectronic devices. Firstly, the detailed effects of Eu3+ and F⁻ doping on the structure and optical properties of CsPbBr1.5Cl1.5 quantum dot glass are discussed. Subsequently, the crystal structure, size distribution, and morphology of CsPbBr1.5Cl1.5 QDs are characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Furthermore, the application of CsPbBr1.5Cl1.5 QDs in LEDs and temperature sensing optoelectronic devices is explored, highlighting their performance and potential value in these applications. This study provides important references and guidance for further research and application of CsPbBr1.5Cl1.5 QDs in the field of optoelectronics.

Effects of B2O3 on the structural evolution and biological behavior of borate bioactive glasses by sol-gel and melting methods

Borate bioactive glasses (BGs) have become indispensable in biomedicine for their exceptional bioactivity and tunable degradation characteristics. This study presents the synthesis and comprehensive evaluation of BGs within the xB2O3-CaO-Na2O-K2O-MgO-P2O5 system, featuring varying compositions of B2O3 (x = 40, 55, and 70 mol.%), using both sol-gel and melting techniques. A systematic investigation of their structural evolution, degradation kinetics, apatite-forming capabilities, and cytotoxicity has been conducted. The results demonstrate that the borate BGs with elevated B2O3 content significantly accelerates the degradation rate and enhances bioactivity across both synthesis methods, as B2O3 content increases from 40 to 70 mol%. Notably, the sol-gel derived BG samples demonstrate pronounced degradation, with mass loss reaching up to 90 %, and superior hydroxyapatite formation in simulated body fluid, surpassing the performance of their melting-derived counterparts. Cytotoxicity assays with MC3T3-E1 cells reveal no significant inhibitory effects from any of the borate bioglasses. Moreover, ab initio molecular dynamics simulations have been utilized to elucidate the relationship between structural alterations and in vitro bioactivity, with a particular emphasis on the boron coordination number. These findings provide a promising strategy for the development of borate BGs with tailored degradation profiles and excellent bioactivity, making them as strong candidates for various biomedical applications.