Structural and magnetic phase transitions in Pr.sub.0.7./sub.Ca.sub.0.3./sub.MnO.sub.3./sub. at high pressures

0356861 - FZÚ 2011 RIV US eng J - Journal Article
Kozlenko, D. P. - Chan, T.A. - Kichanov, S.E. - Jirák, Zdeněk - Dubrovinsky, L.S. - Savenko, B. N.
Structural and magnetic phase transitions in Pr_0.7Ca_0.3MnO₃ at high pressures.
JETP Letters. Roč. 92, č. 9 (2010), 590-594. ISSN 0021-3640. E-ISSN 1090-6487
Institutional research plan: CEZ:AV0Z10100521
Keywords : high pressure * crystal structure * magnetic structure * phase transition
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.557, year: 2010

The crystal structure and Raman spectra of Pr0.7Ca0.3MnO3 manganite at high pressures of up to 30 GPa and the magnetic structure at pressures of up to 1 GPa have been studied. A structural phase transition from the orthorhombic phase of the Pnma symmetry to the high-pressure orthorhombic phase of the Imma symmetry has been observed at P ~ 15 GPa and room temperature. Anomalies of the pressure dependences of the bending and stretching vibrational modes have been observed in the region of the phase transition. A magnetic phase transition from the initial ferromagnetic ground state (TC = 120 K) to the A-type antiferromagnetic state (TN = 140 K) takes place at a relatively low pressure of P = 1 GPa in the low-temperature region. The structural mechanisms of the change of the character of the magnetic ordering have been discussed.
Permanent Link: http://hdl.handle.net/11104/0195271