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在Gd_xTm_(2-x)W_3O_(12)(x=0.5,1和1.5)系列固溶体中,当Gd的含量较低(x=0.5)时,其室温稳定相为正交相;当Gd的含量较高(x=1,1.5)时,其室温稳定相为单斜相,但在高温时转变为正交相。采用高温淬火的方法,使Gd_xTm_(2-x)W_3O_(12)(x=1,1.5)高温时的正交相保留至室温。通过TG-DSC和高温XRD研究了其吸水、相变和热膨胀性,结果表明:当x=0.5时,Gd0.5Tm1.5W_3O_(12)的吸水性较弱,而当x=1和1.5时,其吸水性增强;Gd_xTm_(2-x)W_3O_(12)(x=1,1.5)在500℃以下,其正交相是稳定的;Gd_xTm_(2-x)W_3O_(12)在200~500℃的区间均具有较大的负热膨胀性,并且其负热胀系数随着Gd的含量增加而增大。
In the solid solution of Gd_xTm_ (2-x) W_3O_ (12) (x = 0.5, 1 and 1.5), when the content of Gd is low (x = 0.5), the room temperature stable phase is orthogonal; At higher (x = 1, 1.5), the room temperature stable phase is monoclinic, but transforms into a quadrature phase at high temperatures. The high-temperature quenching of Gd_xTm_ (2-x) W_3O_ (12) (x = 1, 1.5) was carried out at room temperature. The results showed that the water absorption of Gd0.5Tm1.5W_3O_ (12) was weak when x = 0.5, while when x = 0.5, the water absorption, phase transition and thermal expansion were studied by TG-DSC and high temperature XRD. The water absorption of Gd_xTm_ (2-x) W_3O_ (12) (x = 1, 1.5) is stable below 500 ℃; Have larger negative thermal expansion, and their negative thermal expansion coefficient increases with the increase of Gd content.