Paramagnetism and antiferromagnetic d-d coupling in GaMnN magnetic semiconductor

The magnetization of Ga1-xMnxN (x <0.1) crystals was measured as a function of the magnetic field and temperature. Paramagnetic behavior typical of sp in S=5/2 expected for Mn2+ (d(5)) magnetic centers was observed in the temp erature range of 2 K <T < 300 K. On the other hand, antiferromagnetic coupl ing between Mn ions was clearly visible. The nearest neighbor (NN) coupling constant J(NN)/k(B)=-1.9 K was estimated from the temperature dependence o f the magnetization. (C) 2001 American Institute of Physics.