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Related papers: Quantum paraelectric behavior of pyrochlore PMN

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The structure of BaMg1/3Ta2/3O3 (BMT) has been studied using X-ray scattering. The phonons have been measured and the results are similar to those of other materials with the perovskite structure such as PbMg1/3Nb2/3O3 (PMN). The acoustic…

The structure and dielectric properties of 6% $\rm{Sr}^{2+}$-substituted, modified Lead Zirconium Titanate (PZT) piezoelectric ceramic, with composition…

We report the infrared dielectric properties of $\alpha$-quartz in the temperature range from $1.5\ \mathrm{K}$ to $200\ \mathrm{K}$. Using an infrared free-electron laser, far-infrared reflectivity spectra of a single crystal $y$-cut were…

Materials Science · Physics 2019-04-25 Christopher J. Winta , Martin Wolf , Alexander Paarmann

Paramagnetic (PM) properties of columnar cobaltosic oxide (Co3O4) nanoparticles, about 75 nm in diameter, have been investigated by magnetization measurements at T > TN = 39 K. In zero or low applied field, the effective PM moment per…

Materials Science · Physics 2015-05-19 Weimeng Chen , Chinping Chen , Lin Guo

Conventional wisdom dictates that quantum effects become unimportant at high temperatures. In magnets, when the thermal energy exceeds interactions between atomic magnetic moments, the moments are usually uncorrelated, and classical…

We report high $q$-resolution neutron scattering data on PMN-$x$PT single crystals with $x=20%$ and 27%. No rhombohedral distortion occurs in the 20PT sample for temperatures as low as 50 K. On the other hand, the 27PT sample transforms…

Materials Science · Physics 2007-05-23 Guangyong Xu , D. Viehland , J. F. Li , P. M. Gehring , G. Shirane

BaMnF$_4$ microsheets have been prepared by hydrothermal method. Strong room-temperature blue-violet photoluminescence has been observed (absolute luminescence quantum yield 67%), with two peaks located at 385 nm and 410 nm, respectively.…

Materials Science · Physics 2016-01-20 Shuang Zhou , Yakui Weng , Zhangting Wu , Jinlong Wang , Lingzhi Wu , Zhenhua Ni , Qingyu Xu , Shuai Dong

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 transition in the temperature range 1.5…

Materials Science · Physics 2007-05-23 S. N. Gvasaliya , B. Roessli , D. Sheptyakov , S. G. Lushnikov , T. A. Shaplygina

Type-II multiferroics, where spin interactions induce a ferroelectric polarization, are interesting for new device functionalities due to large magnetoelectric coupling. We report on a new type of multiferroicity in the quadruple-perovskite…

A monoclinic phase was recently discovered near the morphotropic phase boundary in several high-performance piezoelectric perovskite solid solutions, but its properties have not been reported. In this paper the dielectric, piezo- and…

Materials Science · Physics 2016-08-31 A. A. Bokov , Z. -G. Ye

We report direct experimental evidence of antiferroelectric to paraelectric phase transition under pressure in NaNbO3 using neutron diffraction at room temperature. The paraelectric phase is found to stabilize above 8 GPa and its crystal…

Materials Science · Physics 2015-06-11 S. K. Mishra , M. K. Gupta , R. Mittal , S. L. Chaplot , Thomas Hansen

We report complex dielectric and Raman spectroscopy measurements in four samples of $\alpha$- Fe$_2$O$_3$, consisting of crystallites which are either hexagonal shaped plates or cuboids. All four samples exhibit the spin reorientation…

Strongly Correlated Electrons · Physics 2019-04-17 Namrata Pattanayak , Jitender Kumar , Partha Pratim Patra , G. V. Pavan Kumar , Ashna Bajpai

We present a correlated {\it ab initio} description of the paramagnetic phase of Tl$_2$Mn$_2$O$_7$, employing a combined local density approximation (LDA) with multiorbital dynamical mean field theory (DMFT) treatment. We show that the…

Strongly Correlated Electrons · Physics 2009-11-11 L. Craco , C. I. Ventura , A. N. Yaresko , E. Müller-Hartmann

We have measured the polarized Raman scattering spectra of Cd2Re2O7, the first superconducting pyrochlore, as a function of temperature. For temperatures below the cubic-to-tetragonal structural phase transition (SPT) at 200K, a peak with…

Materials Science · Physics 2007-05-23 C. A. Kendziora , I. A. Sergienko , R. Jin , J. He , V. Keppens , B. C. Sales , D. Mandrus

Neutron scattering experiments on a polycrystalline sample of the frustrated pyrochlore magnet Tb2Ti2O7, which does not show any magnetic order down to 50 mK, have revealed that it shows condensation behavior below 0.4 K from a thermally…

Disordered Systems and Neural Networks · Physics 2011-12-13 Hiroshi Takatsu , Hiroaki Kadowaki , Taku J. Sato , Jeffrey W. Lynn , Yoshikazu Tabata , Teruo Yamazaki , Kazuyuki Matsuhira

Brillouin spectroscopic measurements have been carried out on relaxor ferroelectric Pb(Zn1/3Nb2/3)0.85Ti0.15O3 (PZN-PT) single crystal over the temperature range 300-585 K. The longitudinal acoustic phonon begins to soften below 650 K,…

Materials Science · Physics 2015-06-05 K. K. Mishra , V. Sivasubramanian , A. K. Arora , Dillip Pradhan

Physical properties of a pyrohafnate compound Pr2Hf2O7 have been investigated by ac magnetic susceptibility \chi_ ac(T), dc magnetic susceptibility \chi(T), isothermal magnetization M(H) and heat capacity C_p(T) measurements on…

The effect of the electron temperature on both the light absorption and the scattering by metal nanoparticles (MNs) with excitation of the surface plasmon electron vibrations is studied in the framework of the kinetic theory. The formulae…

Mesoscale and Nanoscale Physics · Physics 2013-11-25 N. I. Grigorchuk

Single crystals of Nd_{1-x}Pb_{x}MnO_{3} with x=0.2 are grown by high temperature solution growth technique using PbO-PbF_{2} flux. Magnetization studies on the samples show a transition to a ferromagnetic state below T_c ~ 125 K and the…

Strongly Correlated Electrons · Physics 2009-11-07 Anika Kumar , Nilotpal Ghosh , Janhavi P. Joshi , H. L. Bhat , S. V. Bhat

Structural, vibrational and dielectric properties of (Pb1-xBix)(Ti1-xMnx)O3 (PBTM) (0 x 0.50) polycrystalline ceramics have been examined as a function of temperature. Synchrotron-based powder x-ray diffraction was employed to confirm phase…