Structural state of Eu_2(MoO_4)_3 single crystal after different thermobaric treatments

摘要

The X-ray and dilatometric studies of Eu_2(MoO_4)_3 single crystal after different thermobaric treatments were carried out. The compression of the initial fl-phase of Eu_2(MoO_4)_3 single crystal to P=9 GPa at room temperature results in new high-pressure phase (hpp) formation which is retained at decompression to P=1 atm. The hpp phase undergoes phase transition back into fi phase around T=860-880 K at heating. The hpp β phase transition is accompanied by the unusual structure state formation when coherent reflections arc essentially dropped and all x-ray diffraction intensity of the sample is transformed into the background-like spectrum.