Pressure dependence of magnetic properties of CrO2 from theory

From self-consistent electronic structure calculations bulkmodulus of CrO2 (270 GPa) is within agreement of experimental value 280 +/- 20 GPa. At different simulated isotropic compressions the system remains half metallic for 1 < P < 60 GPa then becomes metallic with lowered magnetization for 60 < P < 120 GPa. This is accompanied by decreasing energy difference between the ferro-magnetic ground state and an antiferromagnetic configuration so that both are accessible at high pressures. Spin fluctuation theory analysis points to critical pressure for magnetic order disappearance P-C = 150 GPa and dT(C)/dP = -0.027 K GPa(-1). This positions CrO2 between soft (Invar) and very hard (fcc-Ni) magnetic systems pointing to its magnetic hardness. (c) 2005 Elsevier B.V. All rights reserved.