Ce ( Cu1-xFex )Ge摻雜Fe所造成磁性的影響

Effects of Fe substitution on the Magnetic properties in Ce ( Cu1-xFex ) Ge

甘健瑩(Kan, Jangin)

指導教授 ： 李文新

國立中正大學/理學院/物理學系/碩士(2012年)

摘要

我們以CeCuGe化合物為母樣品，並且利用Fe元素來取代CeCuGe中的Cu，形成CeCu1-xFexGe一系列的樣品。根據CeCuGe之性質，我們加以探討CeCu1–xFexGe其摻雜Fe在晶體結構、磁性及電性所造成的影響。由粉末x光繞射圖數據顯示CeCu1-xFexGe其結構與CeCuGe同為ZrBeSi結構並且其空間組態為P63 / mmc，在摻雜Fe比例到達x = 0.4時有雜相產生，表示其對Fe取代Cu之solubility limit大約在x = 0.3 ~ 0.4間。根據CeCu1-xFexGe磁化率數據顯示發現在低溫下具有鐵磁與反鐵磁相共存之現象。另外以ρ(電阻率)對ln(T)溫度作圖證明當溫度從室溫降至低溫時，電阻率有線性遞增的現象，此為近藤行為( Kondo behavior )的特徵之一。

關鍵字

近藤效應 ； 磁性

並列摘要

As revealed in the powder X-ray diffraction data, the hexagonal structure of the parent compound CeCuGe, which crystallizes in the ZrBeSi-type structure with space group P63/mmc, is retained in Ce(Cu1-xFex)Ge up to the solubility limit near x = 0.3. An interesting phenomenon was found that antiferro- and ferro- magnetism coexisted in the Fe-doped system Ce(Cu1-xFex)Ge in which the parent compound CeCuGe ordered ferromagnetically ~ 10 K only. The low temperature saturation magnetic moment values for all these compounds are well less than the theoretically value 2.14 μB for the free Ce3+ ion involving the entire six-fold J = 5/2 multiplet. The reduced saturation moment in Ce(Cu1-xFex)Ge is ascribed to partial lifting of the 4f-electron level degeneracy via the magnetic, electric and specific heat analyses.

並列關鍵字

CeCu1-xFexGe ； CeCuGe ； Kondo effect ； magnetic properties

參考文獻

[2] N. B. Brandt, V. V. Moshchalkov, Adv. phys. 33 (1984) .

[3] B. Chabot and E. Parthe, J. Less-Commob Met. 97 (1984) .

[5] D. L. Cox Phys. Rev. Lett. 59 (1987) .

Sigrist, and P. Rogl Phys. Rev. Lett. 92 (2004) .

[9] G. R. Stewart Rev. Mod. Phys. 56 (1984) .