Structural study of the high-pressure antiferroelectric phase of CsH/sub 2/PO/sub 4/

Conference · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5424992

Schuele, P J; Thomas, R

A three-dimensional neutron diffraction study has been carried out on the pressure-induced antiferroelectric phase of CsH/sub 2/PO/sub 4/. At 100.7/sup 0/K and a hydrostatic pressure of 3.6 kbar, the unit cell parameters are a = 15.625(9), b = 6.254(2), c = 4.886(1) A, ..beta.. = 108.08(3)/sup 0/ and Z = 4. Atomic parameters were determined using full-matrix least-squares methods which yield final agreement indices: R(F/sup 2/) = 0.0715, R/sub w/(F/sup 2/) = 0.0807 and S = 2.13. The structure is nearly consistent with the monoclinic space group P2/sub 1//a but refinement in P2/sub 1/ yields a slightly better fit. The structure is markedly different from those of the paraelectric and ferroelectric phases with large relative displacements (nearly 1 A) of Cs/sup +1/ and PO/sub 4//sup -3/ groups in the x-z plane. Hydrogens bonding in b-chains, which are disordered in the paraelectric phase, show antiferroelectric order.

• Research Organization: Montana State Univ., Bozeman (USA). Dept. of Physics; Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5424992
• Report Number(s): BNL-36634; CONF-850880-1; ON: DE85013309
• Resource Relation: Conference: 6. international meeting on ferroelectricity, Kobe, Japan, 12 Aug 1985
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACID PHOSPHATES
PHASE TRANSFORMATIONS
ANTIFERROELECTRIC MATERIALS
CRYSTAL STRUCTURE
CESIUM PHOSPHATES
LATTICE PARAMETERS
NEUTRON DIFFRACTION
VERY HIGH PRESSURE
ALKALI METAL COMPOUNDS
CESIUM COMPOUNDS
COHERENT SCATTERING
DIELECTRIC MATERIALS
DIFFRACTION
MATERIALS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
SCATTERING
360602* - Other Materials- Structure & Phase Studies