Magnetic interaction in Mg, Ti, Nb doped manganites |
| |
Authors: | IO Troyanchuk MV Bushinsky H Szymczak K Bärner A Maignan |
| |
Institution: | Institute of Solid State and Semiconductor Physics of National Academy of Sciences, P. Brovka str. 17, 220072 Minsk, Belarus, BY Institute of Physics, Polish Academy of Sciences, al. Lotnikov 32/46, 02-668 Warsaw, Poland, PL 4. Physikalishes Institut der G?ttingen Universit?t, Bunsenstra?e 13, 37073 G?ttingen, Germany, DE Laboratoire CRISMAT, ISMRA, Université de Caen, 6 Boulevard du maré,chal Juin, 14050 Caen Cedex, France, FR
|
| |
Abstract: | An effect of Mn substitution with Me=Mg2+, Ti4+, Nb5+ in manganites has been investigated by preparing La0.7Sr0.3(Mn1-xMex)O3 and La1-xSrx(Mn1 - x/2Nbx/2)O3 series. It was established that substitution of manganese with magnesium up to x = 0.16 leads to a collapse of a long-range ferromagnetic order whereas La0.7Sr0.3(Mn 3 +
0.85Nb 5 +
0.15)O3 is ferromagnet with T
C = 123 K and exhibits a large magnetoresistance below Curie point despite an absence of four-valent manganese. Hypothetical
magnetic phase diagrams are constructed for La0.7Sr0.3(Mn1-xMex)O3 and La1-xSrx(Mn1 - x/2Nbx/2)O3. Our results show that Mn3+-O-Mn3+ exchange interaction is ferromagnetic in the orbitally disordered manganites as well as an increase of Mn4+ content above 50% from a total amount of manganese ions leads to formation of a spin glass state due to a competition between
antiferromagnetic Mn4+-O-Mn4+ and ferromagnetic Mn3+-O-Mn4+(Mn3+) superexchange interactions.
Received 24 January 2002 Published online 9 July 2002 |
| |
Keywords: | PACS 75 30 Kz Magnetic phase boundaries (including magnetic transitions metamagnetism etc ) – 75 30 Vn Colossal magnetoresistance – 75 30 Et Exchange and superexchange interactions |
本文献已被 SpringerLink 等数据库收录! |
|