A systematic study of magnetic order in divalent europium perovskites

• Published in: Journal of solid state chemistry Vol. 19; no. 2; pp. 155 - 160
• Main Authors: Greedan, J.E., Chien, Chai-Ling, Johnston, Richard G.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.01.1976
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/0022-4596(76)90163-8

The magnetic properties of a series of cubic perovskite materials, Eu(Al 0.5Ta 0.5)O 3, Eu(Mg 0.5 W 0.5)O 3, and Eu(Lu 0.5Ta 0.5)O 3 have been investigated using bulk magnetic and Mössbauer techniques. Eu(Al 0.5Ta 0.5)O 3 is a ferromagnet ( T c ∼ 5°K, θ c = + 8°K), Eu(Lu 0.5Ta 0.5)O 3 is an antiferromagnet ( T N = 4.0, θ c = −8°K), while Eu(Mg 0.5W 0.5)O 3 is probably antiferromagnetic ( T N = 2.8°K, θ c = − 1°K). These data are compared with the known properties of EuLiH 3 and EuTiO 3 and a sharp drop in θ c as a function of increasing lattice constant is noted. A molecular field theory analysis of the data yields two possible sets of nn ( J 1) and nnn ( J 2) exchange constants for each compound which are compared with existing theories.