The Ba8Zn_xGe_(46-x-y)□ _y (4 ≤ x ≤ 8, □ = Ge vacancy) solid solution crystallizes in the clathrate type I structure as indicated by X-ray powder diffraction and transmission electron microscopy. The fraction of vacancies (y) derived from electron probe microanalysis varies like y =3.3 — 0.54x for 0 ≤ x ≤ 6 and y = 0 for 6 < x ≤ 8. A simplified band picture can explain how the ratio (2—)/(4—) of formal oxidation numbers of zinc and of vacancy leads to the ～1/2 slope of the y =f(x) relation. Hall effect measurements indicate that the Ba8Zn_xGe_(46-x-y)□ _y definitely deviate from the Zintl rule when 0≤ x < 4, weakly deviate from the the Zintl rule when 4 ≤ x ≤6, and fulfill the Zintl rule when 6 < x≤ 8. Resistivity versus temperature data for 4 ≤ x ≤ 8 are in line with a "bad metal" behavior (x～4) evolving toward a degenerate semiconducting behavior (x～ 8). The Seebeck coefficient increases with x in agreement with the charge carrier concentration variation and reaches —67.1 μV/K in Ba_(7.95)Zn_(7.83)Ge_(38.17) which also displays the largest power factor (PF = 3.75 μW·K~(-2)·cm~(-1) at 300 K) in this series.
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机译：如X射线粉末衍射和透射电子显微镜所示，Ba8Zn_xGe_（46-x-y）□ _y（4 ≤ x ≤ 8，□ = Ge空位）固溶体在包合物I型结构中结晶。从电子探针显微分析得出的空位 （y） 比例变化，例如 y =3.3 — 0.54x 对于 0 ≤ x ≤ 6 和 y = 0 对于 6 < x ≤ 8。简化的带状图可以解释锌的形式氧化数和空位数的比值（2—）/（4—）如何导致y =f（x）关系的~1/2斜率。霍尔效应测量表明，当 0 x < 4 时，Ba8Zn_xGe_（46-x-y）□ _y肯定偏离 Zintl 规则≤当 4 ≤ x ≤6 时弱偏离 Zintl 规则，当 6 < x≤ 8 时， 8 时，肯定偏离 Zintl 规则。4 ≤ x ≤ 8 的电阻率与温度数据一致，符合向简并半导体行为 （x~ 8） 演变的“坏金属”行为 （x~4）。塞贝克系数随载流子浓度变化随x增加，在Ba_（7.95）Zn_（7.83）Ge_（38.17）中达到—67.1 μV/K，功率因数最大（PF = 3.75 μW·K~（-2）·cm~（-1） at 300 K）。
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