我們量測了CeMn2Si2與CeMnCuSi2這兩個混合價鍵系統的磁性與電性。 同時也量測了CeMn2Si2與CeMnCuSi2在溫度為10、50、150及300 K時Ce的價數。 在385 K至50 K之間CeMn2Si2為一個3d反鐵磁相。 當外加磁場為0.1 kOe，溫度為~ 27 K時，CeMn2Si2的零磁場冷卻磁化率χZFC(T)顯示出一個峰而磁場冷卻磁化率χFC(T)則顯示出一個肩膀狀且不論其交流磁化率的實部χ’(T)或是虛部χ”(T)在溫度~27 K處都顯示出一個峰，這建議了在CeMn2Si2中反鐵磁相與自旋玻璃相的並存。 不同於CeMn2Si2對CeMnCuSi2而言，磁化率在150 K處隨溫度的下降而快速的增加，這建議了一個3d傾斜鐵磁性。 當磁場為1 kOe時，在溫度低於150 K時，χZFC(T)隨著溫度的降低而增加，當溫度低於95 K時χZFC(T)與χFC(T)顯著分離，且χZFC(T)在73 K處顯現出一個峰，這指出了一個傾斜鐵磁相到反鐵磁相的磁相變，也建議在CeMnCuSi2中反鐵磁相與自旋玻璃相的共存。 CeMnCuSi2中交流磁化率的實部χ’(T)在溫度~119 K處顯示出一個峰，這個溫度明顯地遠高於CeMn2Si2中χ’(T)峰值處的27 K。 因此，若將CeMn2Si2中50%的Mn離子任意地替換為沒有磁性的Cu離子，自旋玻璃的特質會被明顯地增強。 零磁場冷卻電阻率ρZFC(T)與磁場冷卻電阻率ρFC(T)於95 K處的分離顯示自旋玻璃相的存在，且磁阻與磁化率隨溫度有相同的變化趨勢。 因此，電性的量測也支持，在CeMnCuSi2中反鐵磁相與自旋玻璃相的共存。

We measured the Ce valence of two mixed valence systems CeMn2Si2 and CeMnCuSi2 at 10, 50, 150, and 300 K. In a magnetic field of 0.1 kOe, zero-field-cooling susceptibility χZFC(T) of CeMn2Si2 exhibits a peak and field-cooling susceptibility χFC(T) shows a shoulder at ~ 27 K. Either the real component χ’(T) or the imaginary component χ”(T) of ac-susceptibilities exhibits a peak around ~ 27 K, which suggests a spin-glass phase in CeMn2Si2. For CeMnCuSi2, the temperature dependence of magnetization of CeMnCuSi2 rapidly increases at 150 K, which suggests a 3d canted ferromagnetic magnetism. In a magnetic field of 1 kOe, χZFC increases as the temperature decreases below 150 K. χZFC of CeMnCuSi2 starts to deviate from χFC at ~ 95 K and χZFC displays a peak near 73 K, which indicates a canted ferromagnetic to antiferromagnetic transition and also suggests the coexistence of the antiferromagnetic and spin-glass phases in CeMnCuSi2. The real component of ac-susceptibility χ’(T) exhibits a peak around ~119 K that is considerably higher than 27 K of χ’(T) in CeMn2Si2. Therefore, if 50% of Mn ions of CeMn2Si2 are randomly replaced by nonmagnetic Cu ions, the spin-glass behaviors will be drastically enhanced. The spin-freezing properties of CeMnCuSi2 are further conformed by the resistivity measurements. Therefore, the antiferromagnetic and spin-glass phases are coexisted in the mixed valence system CeMnCuSi2.

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