Magnetic properties of UCu■Ge■ and UPd■Ge■

• Main Authors: Ing-Jye Jang, 張英傑
• Other Authors: Cheng Tien
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/56646574304833033087

碩士 === 國立成功大學 === 物理研究所 === 81 === The coexistence of different magnetic orderings of UCu■Ge■ alloy has been reported in some papers. It shows paramagnetic at room temperature. Ferromagnetism produces at 110 K which resistance's slope changes suddenly and the specific heat shows a small peak. It means a phase transition from paramagnetism to ferromagnetism. Their neutron scattering experiment finds an anti-ferromagnetic transition at 43 K. But the phase transition temperature from susceptibility and the resistance's behavior below the transition temperature haven't the coindence properties , and B- H curve shows hysteresis of ferromagnism. We can find the phase transition from the resistance measurement. However, there is no strange change in the specific heat because of nearly free energy of ferromagnetism and anti-ferromagnetism. We find the similar behavior in UPd■Ge■alloy.First, a phase transition from para-magnetism to anti-ferromagnetism produces at 140K in the resistance and susceptibility measurements. At about 80K, resistance, susceptibility, and specific heat tend to chance slowly. It means some ferromagnetic ordering to produce, however, it is not so intensity to identify a phase transition. At lower temperature,anti-ferromagnetism produce again from susceptibility measurement.We think magnetic oscillation behavior in the sample. And from B-H curve measurement, it shows a hysteresis curve of ferromagnetism. In other word, the sample has anti-ferromagnetism with ferromagnetic behavior. In this paper, in order to compare the behavor of UCu■Ge■ and UPd■Ge■ fairly, we prepare the two samples and measure the X-ray, resistance, susceptibility , and specific heat of them carefully. Finally, we interpret these magnetic properties by the existence of incommensurate phase.