Abstract
We have investigated the effect of partial isovalent anion substitution in on electrical transport and ferromagnetism. Substitution of only 2.4% of As by P induces a metal-insulator transition at a constant Mn doping of while the replacement of 0.4% As with N results in the crossover from metal to insulator for . This remarkable behavior is consistent with a scenario in which holes located within an impurity band are scattered by alloy disorder in the anion sublattice. The shorter mean free path of holes, which mediate ferromagnetism, reduces the Curie temperature from 113 to 60 K (100 to 65 K) upon the introduction of 3.1% P (1% N) into the As sublattice.
- Received 7 February 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.087203
©2008 American Physical Society