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利用B_2O_3助熔剂法结合SPS技术制备了Mg_(2-x)Zn_xSi_(0.99)Sb_(0.01)(0≤x≤0.1)固溶体。测量了300~780 K温度区间内试样的电导率、塞贝克系数和热导率。发现晶格热导率随Zn取代量的增大而降低。而电导率随Zn取代量的增大而先降低后增大。讨论了影响电导率与晶格热导率的变化规律的具体内在机制。所有样品中x=0.075样品的功率因子最高,在780 K达1.76 m W·m~(-1)·K~(-2),比基体Mg_(2-x)Zn_xSi_(0.99)Sb_(0.01)高约18%。x=0.1样品具有最低晶格热导率,在770 K达到2.86 W·m~(-1)·K~(-1)。低晶格热导率使Mg_(1.9)Zn_(0.1)Si_(0.99)Sb_(0.01)具有最高热电优值,在780 K达0.37。
The solid solution of Mg_ (2-x) Zn_xSi_ (0.99) Sb_ (0.01) (0≤x≤0.1) was prepared by using B_2O_3 flux method and SPS technique. The electrical conductivity, Seebeck coefficient and thermal conductivity of the samples in the temperature range of 300 ~ 780 K were measured. The thermal conductivity of the lattice was found to decrease with increasing Zn substitution. The conductivity decreases with the increase of Zn substitution and then increases. The specific internal mechanism that affects the variation of conductivity and lattice thermal conductivity is discussed. The power factor of x = 0.075 is the highest in all the samples, reaching 1.76 mW · m -1 K · (-2) at 780 K. Compared with that of Mg 2-x Zn x Si 0.99 Sb 0.01, About 18% higher. The sample with x = 0.1 has the lowest lattice thermal conductivity and reaches 2.86 W · m -1 K -1 at 770 K. The low lattice thermal conductivity makes the Mg_ (1.9) Zn_ (0.1) Si_ (0.99) Sb_ (0.01) have the highest thermoelectric figure of merit and reaches 0.37 at 780 K.