Low Temperature Physics: 33, 895 (2007); https://doi.org/10.1063/1.2747047 (20 pages)
Fizika Nizkikh Temperatur: Volume 33, Number 11 (November 2007), p. 1181-1205    ( to contents , go back )

New functional compounds AC3B4O12

A.N. Vasiliev1 and O.S. Volkova1,2

1The Moscow State University М.В. Lomonosov , Moscow, 119992, Russia

2Institute Radio Engineerings and Electronics of the Russian Academy of Science, Moscow, 125009, Russia
E-mail: anvas2000@yahoo.com
pos Анотація:

Received November 21, 2006

Abstract

The physical properties of AC3B4O12-typeperovskites, whose structure originates from the simple ABO3 perovskites are reviewed. The A position experiences strong structural distortions and splits into two new positions A and C. In AC3B4O12 compounds the A position with icosahedral oxygen coordination can be occupied by vacancies and large radius cations irrespective of their charge state, i.e., Na+, Cd2+, Ca2+, Sr2+, Y3+, Ln3+, An4+, or even remain empty. The C position with square oxygen coordination can be occupied only by Jahn–Teller cations like Cu2+ and Mn3+. The B position with octahedral oxygen coordination can be filled by transition and nontransition metals Mn3+, Fe3+, Al3+, Cr3+, Ti4+, Mn4+, Ge4+, Ru4+, Ir4+, Ta5+, Nb5+, Ta5+, Sb5+. Some members of the distorted perovskites family possess properties typical of heavy fermion systems, the others demonstrate collinear and noncollinear magnetic structures with high temperatures of magnetic ordering, colossal magnetoresistance and/or high dielectric permittivity. A variety of compounds AC3B4O12 and their unique properties make these materials interesting for practical applications.

PACS: 75.30.–m Intrinsic properties of magneticallyordered materials;
PACS: 75.47.Gk Colossal magnetoresistance;
PACS: 81.05.–t Specific materials: fabrication,treatment, testing, and analysis.

Key words: perovskites, Jahn-Teller cations, collinear and noncollinear magnetic structures.

Download 1283822 byte View Contents