Anomalous crystal-structure distortion at the antiferromagnetic transitionin the layered cobalt oxide Sr2Y0.8Ca0.2Co2O6

Authors
Yamaura, K Huang, Q Erwin, RW Lynn, JW Cava, RJ
Citation
K. Yamaura et al., Anomalous crystal-structure distortion at the antiferromagnetic transitionin the layered cobalt oxide Sr2Y0.8Ca0.2Co2O6, PHYS REV B, 60(13), 1999, pp. 9623-9629
Citations number
22
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B-CONDENSED MATTER
ISSN journal
01631829 → ACNP
Volume
60
Issue
13
Year of publication
1999
Pages
9623 - 9629
Database
ISI
SICI code
0163-1829(19991001)60:13<9623:ACDATA>2.0.ZU;2-T
Abstract
The temperature-dependent crystal structure and magnetic structure of the l ayered Ruddlesden-Popper phase Sr2Y0.8Ca0.2Co2O6 are reported. The crystal structure is orthorhombic below 270 K [Immm; a = 3.84029(7) Angstrom, b = 3 .80691(6) Angstrom, and c = 19.4980(3) Angstrom at 20 K], transformed from tetragonal [I4/mmm; a = 3.82765(6) Angstrom, and c = 19.5795(3) Angstrom at 295 K]. The crystal structure distortion is accompanied by an anomalous te mperature dependence of the degree of buckling of the CoO2 plane and is cor related with the development of anisotropic antiferromagnetic ordering of m agnetic moments [2.93(2)mu(B) per Co at 20 K]. [S0163-1829(99)09437-0].