Study of diffuse scattering under hydrostatic pressure in PbMg1/3Nb2/3O3 (2009)
Padmanabhan, B, Gvasaliya, S N, Roessli, B, Strassle, Th, Cowley, R A, ...
We report measurements of the evolution of the diffuse scattering in a single crystal PbMg1/3Nb2/3O3 as a function of hydrostatic pressure. Upon applying pressure the diffuse scattering intensity...
Diffuse scattering from the lead-based relaxor ferroelectric PbMg_1/3Ta_2/3O_3 (2009)
Cervellino, A., Gvasaliya, S. N., Zaharko, O., Roessli, B., Rotaru, G. M., Cowley, R. A., ...
The relaxor ferroelectric PbMg_1/3Ta_2/3O_3 was studied by single-crystal neutron and synchrotron x-ray diffraction and its detailed atomic structure has been modeled in terms of static...
Coexistence of incommensurate magnetism and superconductivity in Fe_{1+y}Se_xTe_{1-x} (2009)
Khasanov, R., Bendele, M., Amato, A., Babkevich, P., Boothroyd, A. T., Cervellino, A., ...
We report an investigation into the superconducting and magnetic properties of Fe_{1+y}Se_{x}Te_{1-x} single crystals by magnetic susceptibility, muon spin rotation, and neutron diffraction. We find...
Spin-glass state and long-range magnetic order in Pb(Fe1/2Nb1/2)O3 (2009)
Roessli, B., Amato, A., Gvasaliya, S. N., Lushnikov, S. G., Shaplygina, T. A.
We have investigated the magnetic ground-state of the multiferroic relaxor ferroelectric Pb(Fe$_{1/2}$Nb$_{1/2}$)O$_{3}$ with $\mu$SR spectroscopy and neutron scattering. We find that a transition to...
Pressure-induced quenching of the charge-density-wave state observed by x-ray diffraction (2008)
Sacchetti, A., Condron, C. L., Gvasaliya, S. N., Pfuner, F., Lavagnini, M., Baldini, M., ...
We report an x-ray diffraction study on the charge-density-wave (CDW) LaTe$_3$ and CeTe$_3$ compounds as a function of pressure. We extract the lattice constants and the CDW modulation wave-vector,...
Quantum magnets under pressure: controlling elementary excitations in TlCuCl₃ (2008)
Rüegg, Ch., Normand, Bruce, Matsumoto, M., Furrer, A., McMorrow, D. F., Krämer, K. W., ...
We follow the evolution of the elementary excitations of the quantum antiferromagnet TlCuCl₃ through the pressure-induced quantum critical point, which separates a dimer-based quantum disordered...
Quantum magnets under pressure: controlling elementary excitations in TlCuCl₃ (2008)
Rüegg, Ch., Normand, Bruce, Matsumoto, M., Furrer, A., McMorrow, D. F., Krämer, K. W., ...
We follow the evolution of the elementary excitations of the quantum antiferromagnet TlCuCl₃ through the pressure-induced quantum critical point, which separates a dimer-based quantum disordered...
Noncentrosymmetric Commensurate Magnetic Ordering of Multiferroic ErMn2O5 (2008)
Roessli, B., Fischer, P., Brown, P. J., Janoschek, M., Sheptyakov, D., Gvasaliya, S. N., ...
The non-centrosymmetric magnetic structure of ErMn$_2$O$_5$ has been shown to be very similar to that of HoMn$_2$O$_5$ (Vecchini {\it et al.}, 2008 Phys. Rev. B {\bf 77} 134434). The magnetic...
Soft Modes and Relaxor Ferroelectrics (2008)
Cowley, R. A., Gvasaliya, S. N., Roessli, B.
Relaxor ferroelectrics are difficult to study and understand. The experiment shows that at low energy scattering there is an acoustic mode, an optic mode, dynamic quasi-elastic scattering and...
Gvasaliya, S. N., Roessli, B., Kojima, S., Lushnikov, S. G., ...
We show that the neutron diffuse scattering in relaxor ferroelectric (1-x)PbZn$_{1/3}$Nb$_{2/3}$O$_{3}$ - x PbTiO$_{3}$ (x=0.07) consists of two components. The first component is strictly elastic...
Multiple magnon modes and consequences for the Bose-Einstein condensed phase in BaCuSi2O6 (2007)
Ruegg, Ch., McMorrow, D. F., Normand, B., Ronnow, H. M., Sebastian, S. E., Fisher, I. R., ...
The compound BaCuSi2O6 is a quantum magnet with antiferromagnetic dimers of S=1/2 moments on a quasi-2D square lattice. We have investigated its spin dynamics by inelastic neutron scattering...
Lancaster, T., Blundell, S. J., Andreica, D., Janoschek, M., Roessli, B., Gvasaliya, S. N., ...
The rare-earth ferroelectromagnet YMnO3 consists of weakly coupled triangular layers of S=2 spins. Below T_N ~ 70 K muon-spin relaxation data show two oscillatory relaxing signals due to magnetic...
The Structural Phase Transition of the Relaxor Ferroelectric 68%PbMg1/3Nb2/3O3-32%PbTiO3 (2006)
Gvasaliya, S. N., Roessli, B., Cowley, R. A., Kojima, S., Lushnikov, S. G.
Neutron scattering techniques have been used to study the relaxor ferroelectric 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 denoted in this paper as 0.68PMN-0.32PT. On cooling, these relaxor ferroelectrics have a...
Gvasaliya, S. N., Pomjakushin, V., Roessli, B., Straessle, Th., Klotz, S., Lushnikov, S. G.
The crystal structure of the PbMg$_{1/3}$Ta$_{2/3}$O$_3$ (PMT) relaxor ferroelectric was studied under hydrostatic pressure up to $\sim 7$ GPa by means of powder neutron diffraction. We find a...
Reduction of the ordered magnetic moment in YMnO3 with hydrostatic pressure (2005)
Janoschek, M., Roessli, B., Keller, L., Gvasaliya, S. N., Conder, K., Pomjakushina, E.
YMnO3 exhibits a ferroelectric transition at high temperature (~ 900 K) and magnetic ordering at T_N ~ 70 K where the dielectric constant shows an anomaly indicative of the magneto-dielectric effect....
Quasi-Elastic Scattering, Random Fields and phonon-coupling effects in PbMg1/3Nb2/3O3 (2005)
Gvasaliya, S N, Roessli, B, Cowley, R A, Hubert, P, Lushnikov, S G
The low-energy part of the vibration spectrum in PbMg$_{1/3}$Nb$_{2/3}$O$_3$ (PMN) relaxor ferroelectric has been studied by neutron scattering above and below the Burns temperature, T$_d$. The...
Spin fluctuations in the stacked-triangular antiferromagnet YMnO3 (2005)
Roessli, B., Gvasaliya, S. N., Pomjakushina, E., Conder, K.
The spectrum of spin fluctuations in the stacked-triangular antiferromagnet YMnO3 was studied above the Neel temperature using both unpolarized and polarized inelastic neutron scattering. We find an...
Lushnikov, S. G., Gvasaliya, S. N., Katiyar, R. S.
Raman scattering in relaxor ferroelectric PbMg1/3Ta2/3O3 (PMT) was investigated in the single crystalline form in the temperature range of 20 - 295 K. Anomalous temperature dependence of the...
Dynamics of cubic-tetragonal phase transition in KNbO$_3$ perovskite (2004)
Gvasaliya, S. N., Roessli, B., Cowley, R. A., Lushnikov, S. G., Choubey, A., Gunter, P.
The low-energy part of the vibration spectrum in KNbO$_3$ was studied by cold neutron inelastic scattering in the cubic phase. In addition to acoustic phonons, we observe strong diffuse scattering,...
Gvasaliya, S. N., Roessli, B., Sheptyakov, D., Lushnikov, S. G., Shaplygina, T. A.
Neutron scattering investigations were carried out in PbMg$_{1/3}$Ta$_{2/3}$O$_3$ and BaMg$_{1/3}$Ta$_{2/3}$O$_3$ complex perovskites. The crystal structure of both compounds does not show any phase...
Gvasaliya, S. N., Lushnikov, S. G., Roessli, B.
The low-energy part of vibration spectrum in PbMg$_{1/3}$Nb$_{2/3}$O$_3$ relaxor ferroelectric was studied by inelastic neutron scattering. We observed the coexistence of a resolution-limited central...