High-pressure effects on the crystal and magnetic structure of managanites

Abstract

Nuetron diffraction studies of high-pressure effects on the crystal and magnetic structure of A1-x A ′ MnO3 manganites (A = Pr, La; A′ = Sr, Ca, Na) are reviewed. High pressure leads to various changes in the magnetic structure of manganites: the appearance of a new A-type antiferromagnetic (AFM) state in compounds with the initial ferromagnetic (FM) or pseudo-CE type AFM state, such as La1 − x Ca x MnO3 (x = 0.25, 0.33), Pr1 − x Sr x MnO3 (x = 0.48), Pr0.7Ca0.3Mn1 − y Fe y O3 (y = 0, 0.1), Pr1 − x Na x MnO3 (x = 0.2, 0.25); and the appearance of a new C-type AFM state in the Pr0.44Sr0.56MnO3 compound with the initial A-type AFM state. The observed changes in the magnetic structure and the behavior of the transition temperature to the FM state under high pressure are discussed in the framework of the current theoretical concepts.