Evidence of magnetoelastic spin ordering in dilute magnetic oxides

Parallel spin alignment under moderate magnetic fields has been reported in numerous magnetically dilute oxides at temperatures above 300 K. It is proposed that magnetoelastic effects from 3d(n) series ions with Jahn-Teller orbital occupancy cause lattice-assisted paramagnetism. Theoretical models are offered for the magnetoelastic properties and for the high spin-ordering temperature that is limited by the lattice Debye temperature (similar to 500 K). Measurement data from Fe+Cu and Cr in In(2)O(3) are examined, and spin ordering in magnetically dilute TiO(2), SnO(2), (Ba,Sr)TiO(3), ZnO, and GaAs is discussed.