Liu Zun-Xiao

Magnetic excitations in amorphous Sm-Ni thin films☆

Abstract The temperature dependence of magnetization has been studied for amorphous Sm x Ni 1 -x thin film alloys. It was found that both spin wave excitations and Stoner excitations occur in the temperature range 70–200 K, and a marked deviation from the T 3/2 law was noted below 70 K. Kaneyoshis theory was used to account for the deviation.

Peak Effects in EuBa2Cu3Oy Crystal Prepared by Melt-Textured Growth Method

The magnetization curves of EuBa2Cu3Oy crystal prepared by melt-textured growth method were measured from 1.5 to 87 K up to field 7.5 T for H || C and H ⊥ C. Peak effects were observed at 60, 70 and 73 K for H || C, and 70, 73 and 77 K for H ⊥ C. It is shown that the magnetic field Hp at which the magnetization or critical current reach their extremum is approximately independent of temperature and the peak effects observed can be explained by matching effects.

Low temperature magnetic excitations in amorphous light rare-earth-transition-metal thin films

Abstract The temperature dependence of magnetization has been studied on amorphous RT (R = Ce, Pr, Nd: T = Fe, Co, Ni) thin films. It was found that both spin wave excitations and band excitations exist for most RFe samples in temperature range T 0 –200K, and a marked deviation from Bloch T 3 2 is noted at T T 0 in all RT samples. T 0 is the temperature below which the T 3 2 law is unsuitable to describe the temperature dependence of the magnetization. T 0 ranges from 10 to 100 K. The deviation is accounted for the magnetic structure transition and can be explained by Kaneyoshis theory.

Ge Film Contacts to Radio Frequency Sputtered Y-Ba-Cu-O Superconductor Film

The semiconductor-superconductor contact system of Ge/Y-Ba-Cu-O (YBCO)/SrTiO3 has been successfully fabricated by two steps of deposition. The YBCO film in the contact of Ge/YBCO did not lose its superconductivity and its Tc (on set) did not degrade as well. The top layer of Ge was polycrystalline with preferred orientation corresponding to the epitaxial structure of the underlayer of YBCO.

Superconductivity of Tl2Ba2(Ca1-xMgx)2Cu3 Oy

The structural, magnetic and superconducting properties of the Tl2Ba2 (Ca1-xMgx)2Cu3Oy system with x=0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5 were studied. Replacement of calcium by magnesium depresses Tc from 116.3K (x=0) to 93.3K (x=0.5). The critical current also decreases with increasing x.