Investigation of the transition from ferromagnetic to antiferromagnetic order in the CeMn2(GexSi1−x)2 system

摘要: Samples in the alloy system CeMn2(GexSi1−x)2 exhibit a crossover from antiferromagnetic ordering for CeMn2Si2 to ferromagnetic CeMn2Ge2 as function of concentration. The low temperature behavior samples range 0.0≤x≤1.0 using techniques dc magnetization, ac susceptibility, and thermal expansion were studied. From this we have determined magnetic phase diagram which shows four concentration regions qualitatively different behavior. Increasing substitution Ge Si depression TN gradual development order at T≊305 K. For 0.42≤x≤0.60 there is clear transition K followed by sharp drop magnetization lower temperatures. all susceptibility peak near 300 indicating onset that temperature. Neither nor measurements show anomalies below Tc. There evidence mixed be...