Pressure effects on crystal structure, magnetic and transport properties of layered perovskite

✍ Scribed by A. Podlesnyak; S. Streule; K. Conder; E. Pomjakushina; J. Mesot; A. Mirmelstein; P. Schützendorf; R. Lengsdorf; M.M. Abd-Elmeguid

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 143 KB
• Volume: 378-380
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.01.405

✦ Synopsis

The complex behavior of the RBaCo 2 O 5:5 perovskites, which include a metal-insulator (MI) as well as successive magnetic (PM ! FM ! AFM) transitions, is suggested to be related to an interplay between spin, charge and orbital degrees of freedom of the Co 3þ ions. We have investigated the effect of pressure on the structural, magnetic and electronic properties of TbBaCo 2 O 5:5 by means of neutron powder diffraction (p ¼ 1:2 GPa), magnetization (p ¼ 1:2 GPa), and resistivity measurements (p ¼ 2:6 GPa), respectively. Contrary to the results reported on conventional (La,Sr)CoO 3 perovskites, we find that the pressure coefficients of the transition temperatures T N , T C , as well as T MI are rather small (o1 K=GPa), suggesting a weak change of the spin states at the MI transition. We further show, that pressure and temperature have different effects on the volumes of the CoO 6 octahedron and CoO 5 pyramid in the layered double-perovskite.