本研究以Sn助熔劑長晶法製備單晶籠狀結構三元錫化物M5Rh6Sn18 (M = Sc, Y, Lu)，並利用XRD對樣品粉末進行晶體結構鑑定，所有樣品皆為tetragonal Dy5Co6Sn18-type phase，無其他結構項存在。為了了解其傳輸性質，我們將測量這一系列合金的磁化率(χ)、電阻率(ρ)、熱電係數(S)及熱傳導率(κ)。由磁化率量測結果得知當M5Rh6Sn18 (M=Sc,Y,Lu)系列樣品溫度低於其相變溫度時，均由包利順磁性(Pauli paramagnetism χ>0)迅速地轉變為逆磁性(Diamagnetism χ<0)，可推測所有樣品均進入了超導態，其超導臨界溫度TC分別為5 K、3 K、4 K。由電阻率實驗數據得知，此系列樣品的室溫電阻率相當大約為0.2 mΩ-cm，電阻率隨溫度沒有太大的變化，顯示出此系列樣品具有半金屬電阻特性。由熱電係數的量測發現此系列合金的熱電係數皆為負值，指出其主要傳輸載子為電子。在熱傳導率方面，藉由Wiedemann-Franz law求出電子的熱傳導率(κe)進而得出晶格的熱傳導率(κL)，發現此系列合金在低溫時主要由晶格熱傳導率(κL) 貢獻，而在高溫時則是電子熱傳導率(κe) 貢獻較大，值得一提的是室溫晶格熱傳導率約為2 W/m-K ，這樣相對小的晶格熱傳導率可歸因於籠狀晶體結構。由於籠狀結構內部的原子自由地在籠子內震動，增強了聲子散射效應導致晶格貢獻的熱傳導率大幅降低。M5Rh6Sn18 (M=Sc,Y,Lu)在室溫時熱電優值ZT分別為0.004、0.0015、0.005。

Single crystals of M5Rh6Sn18 (M = Sc, Y, Lu) have been successfully grown by Sn self-flux method and their tetragonal structures have been identified by the x-ray diffraction. We further carried out the temperature-dependent magnetic susceptibility, electrical resistivity, Seebeck coefficient, and thermal conductivity measurements on these single crystals. The observed diamagnetic behavior in the magnetic susceptibility below a transition temperature Tc = 5 K、3 K、4 K confirm the occurrence of the bulk superconductivity in Sc5Rh6Sn18, Y5Rh6Sn18, and Lu5Rh6Sn18. We found that Sc5Rh6Sn18, Y5Rh6Sn18, and Lu5Rh6Sn18 exhibit semi-metallic behavior with weak temperature dependence in their electrical resistivity. For all studied materials, the sign of the Seebeck coefficients is negative, indicating that electrons are dominant carriers for the transport. It is noticeable that the room-temperature lattice thermal conductivity values of these samples are of about 2 W/m-K. Such a relatively low lattice thermal conductivity can be attributed to their caged-type crystal structure which has an effect for reducing the lattice thermal conductivity. Finally, the highest room-temperature ZT value of 0.005 for Lu5Rh6Sn18 was obtained.

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