Y.Z. Yang
,
Y.H Luo
,
Q.S. Li
,
Y.L. Zhu
,
X.M. Ma
,
Y.D. Dong and Y.Z. Chuang(Department of Materials Science and Engineering
,
Guangdong University of Technology
,
Guangzhou510090
,
China)(Guangdong Educational College
,
Guangzhou 510084
,
China)(Department of Materials Science and Engineering
,
Shanghai University
,
Shanghai 200072
,
China)(Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The structural transformation in Fe-Cu powder induced by mechanically driven alloying has been monitored by the lattice constant measurements and Mossbauer spectroscopy. For the samples with Cu higher than 75at.% Mossbauer the spectra show a broad paramagnetic doublet; for samples with 50 and 60at.%Cu a new broad ferromagnetic sextet; for those with less than 30at.%Cu similar to those of α-Fe. The main peaks of the hyperfine field distribution significantly broaden and shift to a lower position with increasing Cu content due to the complex environments of iron atoms in the solid solutions and the reduction in the nearest neighbor Fe of a cental Fe atom, respectively. The saturation magnetization of Fe-Cu alloys monotonously decreases with Cu content. The complex composition dependence of coercive field for the milled samples is discussed with respect to the solid dissolution, grain size, interfacial state etc.. The increase of lattice constants with the solute content in the two terminal solid solutions has been explained by the volume-size factor theory or magnetovolume effect.
关键词:
mechanical alloying
,
null
,
null
,
null
B.W. Wang
,
H. Shen
金属学报(英文版)
Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.
关键词:
solar selective thin film
,
null
,
null
,
null