Magnetic ordering in Gd monopnictides: Indirect exchange versus superexchange interaction

Authors

Chun-gang Duan, University of Nebraska-LincolnFollow
Renat F. Sabiryanov, University of Nebraska - OmahaFollow
Wai-Ning Mei, University of Nebraska at OmahaFollow
Peter A. Dowben, University of Nebraska-LincolnFollow
Sitaram Jaswal, University of NebraskaFollow
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow

Date of this Version

3-9-2006

Comments

Published Applied Physics Letters 88 (2006. Permission to use.

Abstract

The exchange interaction parameters of Gd monopnictides are deduced from fitting the total energies of different magnetic configurations to those computed within the Heisenberg model. The magnetic structures predicted by first-principles calculations as well as the Curie (Néel) temperatures obtained from Monte Carlo simulations are both in good agreement with experiments. A detailed analysis of the exchange parameters suggests that the Ruderman-Kittel-Kasuya-Yosida-type indirect exchange interactions and antiferromagnetic superexchange interactions coexist in these compounds. The magnetic order changes from ferromagnetic in GdN to antiferromagnetic in other Gd pnictides as a result of the increased ionic radius of a pnictide in the latter. ©2006 American Institute of Physics