QUANTITATIVE-ANALYSIS OF THE COMPLEX MAGNETIC PHASE-DIAGRAM OF HOALGA

A recent self-consistent periodic-field model, set up for long-period magnetic systems, is shown to give a satisfactory quantitative description of the main features of a complex magnetic phase diagram below T(N) of an antiferromagnet, namely the hexagonal HoAlGa compound. From the crystal-field and exchange parameters it has been possible to account for (i) the multistep magnetization processes with the correct values of the transition field and the intermediate structures along the easy axis, (ii) magnetization curves along the hard axes, (iii) the amplitude and direction of each moment during all these processes, (iv) the reduced value of the specific-heat discontinuity of the lambda anomaly at t(N).