Anomalies in the magnetic properties of nickel fluorosilicate at high pressures and ultralow temperatures
Galkin A. A. , Vitebskii I. M. , D'yakonov V. P. , Fita I. M., Tsintsadze G. A.
The effect of pressure on the temperature and nature of the magnetic ordering in NiSiF6«6H20 has been studied for the first time. A P-T phase diagram has been constructed. A region in which a paramagnetic phase is stable and regions in which two ferromagnetic phases are stable touch at a triple point on this phase diagram, and the derivative dTc/dP changes sign at this point. The two ferromagnetic phases are an easy-axis phase and an easy-plane phase.