For most silicates, controlling the crystallization - through nucleation, growth, and stabilization of distinct crystalline phase is critical to achieving desired physical properties in final glass-ceramic product. In this context, lead metasilicate PbSiO3 (PS) represents an ideal model system for investigating structural evolution under varying pressure temperature conditions. This primarily due its Raman signatures capability resolving structure with high precision diffraction...

This study investigated the effects of plasma electrolytic oxidation (PEO) treatment in a Ca- and P-rich electrolyte on surface Ti-6Al-4V alloy with distinct α/β phase proportions previously induced by heat treatments. The results revealed that were successfully altered temperatures, forming α plates surrounded β precipitates. PEO-treated samples exhibited thick microsized porous TiO2 coating anatase rutile crystalline forms. oxide layer was depleted Al V atoms, while Ca P gradually enriched...

A remarkable hardening (~ 30 cm-1) of the normal mode vibration associated with symmetric stretching oxygen octahedra for Ba2FeReO6 and Sr2CrReO6 double perovskites is observed below corresponding magnetic ordering temperatures. The very large magnitude this effect its absence anti-symmetric provide evidence against a conventional spin-phonon coupling mechanism. Our observations are consistent collective excitation formed by combination vibrational oscillations local Fe or Cr 3d Re 5d...

We report a structural-magnetic investigation by x-ray absorption spectroscopy (XAS), neutron diffraction, dc susceptibility $({\ensuremath{\chi}}_{\text{dc}})$, and electron spin resonance (ESR) of the 12R-type perovskite ${\text{BaTi}}_{1/2}{\text{Mn}}_{1/2}{\text{O}}_{3}$. Our structural analysis diffraction supports existence trimers with chemically disordered occupancy ${\text{Mn}}^{4+}$ ${\text{Ti}}^{4+}$ ions, valence Mn ions confirmed XAS measurements. The magnetic properties are...

Abstract Experimentally achieving extreme thermodynamical conditions of temperature, pressure and magnetic field such as the ones found in interior planets stars has been a dream to many scientists seeking reproduce those on earth study produce unconventional materials. The advent 4 th generation Brazilian synchrotron source (named after “Sirius” star) allows us get closer this by implementing state-of-the-art beamline facility samples under means multitude x-ray techniques. EMA Beamline...

Raman scattering experiments on LaFeAsO with distinct antiferromagnetic (${T}_{\text{AFM}}=140$ K) and tetragonal-orthorhombic (${T}_{S}=155$ transitions show a quasielastic peak (QEP) in ${B}_{2g}$ symmetry (2 Fe tetragonal cell) that fades away below $\ensuremath{\sim}{T}_{\text{AFM}}$ is ascribed to electronic nematic fluctuations. A scaling of the reported shear modulus $T$ dependence QEP height rather than area indicates magnetic degrees freedom drive structural transition. The large...

Abstract Glass and glass ceramics are very functional materials, albeit their structural complexity. Their relevance ranges from fundamental science problems in the fields of physics, chemistry, geoscience, to applications health areas, engineering, or technological matters that require high performance. Enhancing our understanding these materials' performance refining sample preparation methods remains paramount this field. Synchrotron facilities offer a suite powerful techniques for...

Low-dimensional metal halide compounds, usually described as low-dimensional perovskites, present exciting properties functional materials for a broad range of optoelectronic applications. These compounds are characterized by intense photoluminescence (PL), narrow emission line width, and high exciton binding energy. In particular, the mechanism behind strong green zero-dimensional compound Cs4PbBr6 has been subject debate. As property-tuning tool, hydrostatic pressure was used to...

The crystal lattice of Sr$_2$IrO$_4$ is investigated with synchrotron X-ray powder diffraction under hydrostatic pressures up to $P=43$ GPa and temperatures down $20$ K. tetragonal unit cell maintained over the whole pressure range, within our resolution sensitivity. $c$-axis compressibility $\kappa_c(P,T) \equiv -({1} / {c}) ({d c} {d P})$ presents an anomaly at $P_1=17$ fixed $T=20$ K that not observed $T=300$ K, whereas $\kappa_a(P,T)$ nearly temperature-independent shows a linear...

The series of intermetallic compounds $R{\mathrm{NiSi}}_{3} (R=\text{rare} \text{earth})$ shows interesting magnetic properties evolving with $R$ and metamagnetic transitions under applied field for some the compounds. microscopic structures must be determined to rationalize such rich behavior. Here, resonant x-ray diffraction experiments are performed on single crystals ${\mathrm{GdNiSi}}_{3}$ ${\mathrm{TbNiSi}}_{3}$ at zero field. primitive unit cell matches chemical below N\'eel...

Raman scattering, synchrotron x-ray diffraction, specific heat, resistivity and magnetic susceptibility measurements were performed in Sr(Fe1-x Co x )2As2 [[Formula: see text]] single crystals with superconducting critical temperature [Formula: text] K two additional transitions at 132 152 observed both heat data. A quasielastic signal B 2g symmetry (tetragonal cell) associated electronic nematic fluctuations is observed. Crucially, this shows maximum intensity K, marking the transition...

${\mathrm{HoNiSi}}_{3}$ is an intermetallic compound characterized by two successive antiferromagnetic transitions at ${T}_{N1}=6.3\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and ${T}_{N2}=10.4\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Here, its zero-field microscopic magnetic structure inferred from resonant x-ray diffraction experiments on a single crystalline sample that complement previous bulk susceptibility data. For $T<{T}_{N2}$, the primitive unit cell matches chemical cell. The features...

The characteristic photon emissions in low-dimensional hybrid perovskites are strongly related to inherent distortions the crystal lattice. These cooperative distortions, influenced by organic spacers and confined BX6 octahedra...

The lack of superconductivity in the family materials $A{B}_{2}{\mathrm{As}}_{2}$ $(A=\mathrm{Sr},\mathrm{Ba}$ and $B=\mathrm{Cr},\mathrm{Mn})$ under doping or pressure is an intriguing issue, considering resemblance these to their cousin superconductors $(\mathrm{Ba},\mathrm{Sr}){\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$. In this context, suppression magnetism together with presence electron hole pockets Brillouin zone seem be fundamental ingredients explain superconductivity. paper, we report a...

A Raman spectroscopy study on high quality single crystals of SrCr2 As2 (SCA) in the temperature T range 4 K < 300 and applied magnetic fields up to H = 9 is presented. The chromium B 1g phonon analysis reveals two anomalous shifts frequency, first below 250 at 0 saturated AFM G-type order likely due an enhanced electron-phonon coupling by order, whereas second anomaly occurs above as a consequence magnetostructural displacive transition. Renormalization electronic spectra both studies...

Glass and glass ceramics are very functional materials, albeit their structural complexity. Enhancing our understanding of these materials performance refining sample preparation methods remains paramount. Synchrotron facilities offers powerful techniques for detailed characterization glasses ceramics. These provide insights into atomic molecular structure, phase transformations, mechanical behavior, thermal properties, ultimately contributing to the development improved a wide range...

A perovskita LaMnO3 apresenta antiferromagnetismo abaixo da temperatura de Neel TN[1], ja na BaTiO3 o deslocamento dos ions Ti sua posicao central no octaedro TiO6 faz surgir um momento dipolo eletrico celula unitaria, favorecendo aparecimento dominios ferroeletricos[2]. sintese materiais que possuam caracteristicas magneticas e eletricas pode gerar interessantes prototipos dispositivos armazenamento dados sejam sensiveis as duas propriedades sistema Ba1−x Lax Ti0,5 Mn0,5 O3 nos permite...

We report a structural/magnetic investigation by X-ray absorption spectroscopy (XAS), neutron diffraction, dc-susceptibility ($\chi_{\mbox{dc}}$) and electron spin resonance (ESR) of the 12R-type perovskite BaTi$_{1/2}$Mn$_{1/2}$O$_{3}$. Our structural analysis diffraction supports existence trimers with chemically disordered occupancy Mn$^{4+}$ Ti$^{4+}$ ions, valence Mn ions confirmed XAS measurements. The magnetic properties are explored combining $X$-band ($9.4$ GHz) resonance, both in...