Calculations of EuTe magnetic phase diagram for external pressure

The magnetic phase diagram of europium telluride, EuTe, under external high pressure is theoretically investigated. Besides nearest-neighbour and next -nearest-neighbour exchange interactions, the long-range dipolar and biquad ratic interactions are taken into account. The functional dependences of th ese interactions on the lattice constant are proposed. The calculated Neel and Curie temperatures are compared with the experimental data. Two new pha ses, antiferrimagnetic and ferrimagnetic, have been found at a high pressur e and low temperatures.