Structural Transition of Gd₂O₃:Eu Induced by High Pressure

The structural transition of bulk and nano-size Gd₂O₃:Eu are studied by high pressure energy disperse x-ray diffraction (XRD) and high pressure photoluminescence. Our results show that in spite of different size of Gd₂O₃ particles, the cubic structure turns into a possible hexagonal one above 13.4GPa. When the pressure is released, the sample reverses to the monoclinic structure. No cubic structure presents in the released samples. That is to say, the compression and relaxation of the sample leads to the cubic Gd₂O₃:Eu then turns into the monoclinic one.