Using theoretical arguments, we show that, in order to exploit half-metallic ferromagnets in tunneling magnetoresistance (TMR) junctions, it is crucial to eliminate interface states at the Fermi level within the half-metallic gap; contrary to this, no such problem arises in giant magnetoresistance elements. Moreover, based on an a priori understanding of the electronic structure, we propose an antiferromagnetically coupled TMR element, in which interface states are eliminated, as a paradigm of materials design from first principles. Our conclusions are supported by ab-initio calculations.
@article{arxiv.cond-mat/0506079,
title = {Half-metallic ferromagnets for magnetic tunnel junctions},
author = {Phivos Mavropoulos and Marjana Lezaic and Stefan Bluegel},
journal= {arXiv preprint arXiv:cond-mat/0506079},
year = {2007}
}