Are half-metallic ferromagnets half metals? (invited)

Authors

• Peter A. Dowben, University of Nebraska-LincolnFollow
• Ralph Skomski, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

January 2004

Comments

Published Journal of Applied Physics 95 (2004) 7453-7458. Permission to use.

Abstract

Several classes of materials are currently under investigation as potential high-spin-polarization materials. Unfortunately, the proposed half-metallic materials, including the semi-Heusler alloys, the manganese perovskites, and the "simpler" oxides such as chromium dioxide and magnetite, suffer from fundamental limitations. First, the postulated half-metallic systems lose their full (T = 0) spin polarization at finite temperatures and, second, surfaces, interfaces, and structural inhomogenities destroy the complete spin polarization of half-metallic systems even at zero temperature. In a strict sense, half-metallic ferromagnetism is limited to zero temperature since magnon and phonon effects lead to reductions in polarization at finite temperatures. ©2004 American Institute of Physics.