Gd3+掺杂La2Mo2O9的相稳定性及热导率研究

Phase stability and thermal conductivity of Gd3+ doped La2Mo2O9

摘要:

La₂Mo₂O₉具有极低的热导率,但其在580 ℃左右会发生ɑ-β相变,严重影响其性能和应用。本文以Gd₂O₃掺杂 La₂Mo₂O₉制备了一系列La_2-xGd_xMo₂O₉(x = 0 ~ 0.5)固溶体,研究了掺杂Gd^₃₊对La₂Mo₂O₉相稳定情况和热导率的影响。结果表明,随着Gd^₃₊掺杂量的增加,相变得到有效抑制,当x ≥ 0.2时样品以β相存在。样品的热导率随Gd^₃₊掺杂量的增加先降低后增加,常温下在x = 0.2左右时达到最低,此后缓慢上升,但所有样品的热导率均小于1 W/(m.K)。

Abstract:

La₂Mo₂O₉ is expected to have an extremely low thermal conductivity. However, the α-β phase transition at 580 oC seriously affects its performance and applications. In this work, the effect of Gd^₃₊ doping on the phase stability and thermal conductivity was investigated. The results show that the phase transition of La₂Mo₂O₉ is effectively suppressed with the doping of Gd^₃₊ ions. The samples show a β-phase when x ≥ 0.2. Moreover, the thermal conductivity decreases firstly and then increases with the increase of doping content of Gd^₃₊ ions with a minimum value at x = 0.2 at room temperature. The thermal conductivities of all samples are below 1 W/(m.K).