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我们用金刚石压砧装置（ＤＡＣ）高压Ｘ射线粉末衍射照相方法，研究了β－ＢａＢ＿２Ｏ＿４晶体的相变。压力从０．１ＭＰａ逐步加至１７．６ＧＰａ，发现ＢＢＯ由室温下的六方相经历了若干次相变后，当压力加至１１．５ＧＰａ时，转变为无定形相。在１１．５ＧＰａ压力前的相变是可逆的，一旦进入无定形相，则相变是不可逆的。
We studied the phase transformation of β-BaB_2O_4 crystal by high-pressure X-ray powder diffraction photography with a diamond anvil device (DAC). The pressure was gradually increased from 0.1 MPa to 17.6 GPa and BBO was found to undergo several phase transitions from a hexagonal phase at room temperature and to an amorphous phase when the pressure was increased to 11.5 GPa. The phase transition before the pressure of 11.5 GPa is reversible, and once it enters the amorphous phase, the phase transition is irreversible.