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Effective-medium theory and inelastic neutron scattering are used to study the magnetic excitations in the Ising ferromagnet LiHoF4 near its magnetic-field-induced quantum phase transition (QPT). As expected, the dominant mode softens at the QPT, but reach ...
We report Raman spectroscopy in all four phases of a (K0.5+delta Na0.5-delta)NbO3 (delta similar to 0.03) crystal and ((K0.5+delta Na0.5-delta)(1-x)Li-x)NbO3 for x=0.02 and 0.03. The phase transitions in the Li-free crystal are homogeneous and hysteretic, ...
We have extended the range of the high-pressure optical spectroscopy to the far-infrared region keeping the accuracy of ambient-pressure experiments. The developed method offers a powerful tool for the study of pressure-induced phase transitions and electr ...
Ferroelectric perovskites exhibit superior dielectric, piezoelectric and ferroelectric properties. Architecting ferroelectrics in the small scale holds interest in both application and fundamental research. Compared to their 2D counterparts – thin films, f ...
The pressure-temperature-electric field phase diagram of Fe2OBO3 is studied under ambient and high pressure using resistivity and thermoelectric power measurements. The onset of the incommensurate charge order at T-CO=340 K does not depend on pressure up t ...
We use femtosecond x-ray diffraction to probe directly the structural dynamics of a charge ordered and orbitally ordered thin film of La0.42Ca0.58MnO3 initiated by an ultrafast optical pulse. At low excitation fluences we observe the displacive excitation ...
The decoupled layer quasi-two-dimensional glass phase of c-axis vortices in optimally doped Bi2Sr2CaCu2O8+delta (BSCCO) exhibits low-temperature metastability, the onset temperature of which is coincident with the peak in depinning current for zero-field-c ...
Pressure-induced successive phase transitions of micro-, submicro-, and nanocrystalline NaNbO3 particles were investigated by high-pressure Raman spectroscopy. Microcrystalline NaNbO3, which stabilizes in an orthorhombic Pbcm structure at ambient pressure, ...
Phase transitions in micro-, submicro-, and nanocrystalline NaNbO3 were investigated by temperature-tuning Raman spectroscopy and X-ray powder diffraction method. Three powders with different average particle size showed successive phase transitions within ...
Raman scattering and optical birefringence were used in to investigate a low-temp. phase transition in a single crystal of the 2D Na5RbCu4(AsO4)4Cl2. Phonon anomalies point to a 1st-order nature of the transition. The obsd. transition is most probably rela ...
