High temperature phases with wurtzite-derived structure in Zn2LiGaO4-ZnO alloy system
High temperature phases with wurtzite-derived structure in Zn2LiGaO4-ZnO alloy system
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Zn2LiGaO4-ZnO 合金体系中具有纤锌矿结构的高温相
DOI：
10.1016/j.jallcom.2016.06.249
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Omata
中科院分区：
文献类型：
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作者：
M. Kita;T. Fukada;S. Yamaguchi;T. Omata
我们利用原位高温 X 射线衍射 (XRD)、室温 XRD 和选区电子衍射对 873 K 以上的高温淬火样品研究了 Zn2LiGaO4（一种宽带隙为 4.0 eV 的四元氧化物半导体）及其与 ZnO 合金的结构相变。在他们(Zn2LiGaO4)1/4–(1−y)ZnO合金体系。首先是低温相，即 I 相，其中组成阳离子的排序与 Cd2AgGaS4 型结构中的类似。第一相的不相称调制矢量为 1.04b*，在 <1070 K 下稳定，成分为 0.96 ≤y≤ 1，在室温下稳定（fory= 0.92）。第二相，即 II 相，出现在 773–1373 K 的中间温度，0.96 ≤ y ≤ 1，其不通约调制矢量为 1.08b*。第三相不具有长程阳离子有序性，但仍具有短程阳离子有序性，在高温下 0.92≤y≤1 稳定，从室温到高温 0.2≤y< 0.92 稳定。我们根据晶体结构以及-Zn-O-Zn-O-和-Li-O-Ga-O-键之间的热膨胀失配讨论了三相之间转变的驱动力。
We investigated the structural phase transformations of Zn2LiGaO4, which is a quaternary oxide semiconductor with a wide band gap of 4.0 eV, and its alloys with ZnO by using in-situ high-temperature X-ray diffraction (XRD), room-temperature XRD and selected-area electron diffraction of samples quenched from high temperatures of >873 K. Three types of phases with the wurtzite-derived structure were found in they(Zn2LiGaO4)1/4–(1−y)ZnO alloy system. First is the low-temperature phase, phase I, in which constituent cations are ordered similarly to those in a Cd2AgGaS4-type structure. Phase I has an incommensurate modulation vector of 1.04b* and is stable at <1070 K and compositions of 0.96 ≤y≤ 1 and is stable at room temperature fory= 0.92. The second phase, phase II, appears at intermediate temperatures of 773–1373 K at 0.96 ≤ y ≤ 1, and its incommensurate modulation vector is 1.08b*. Phase III, which has no long-range cation ordering but still has short-range cation ordering, is stable for 0.92 ≤y≤ 1 at high temperatures and for 0.2 ≤y< 0.92 from room temperature to high temperatures. We discuss the driving force of the transformations among the three phases in terms of their crystal structure and the mismatch in thermal expansion between –Zn–O–Zn–O– and –Li–O–Ga–O– linkages.