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Ko, Jeong-Dae;Hong, Sung-Rak
- Korean Journal of Materials Research
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- v.11 no.10
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- pp.859-862
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- 2001
The crystal structure and magnetic properties of the $Ni_{1-x} Cd_xFeAlO_4$(0$\leq$x$\leq$0.5) have been investigated by means of X-ray diffractometry and Mossbauer spectroscopy. The samples($0\leq$x$\leq$0.5) have been prepared by the ceramic sintering method. The X-ray diffraction pattern shows that the crystal structure of the samples is a cubic spinel type. The lattice constant has been found by extrapolation using the Nelson- Riley function and it increases slightly from $8.321{\AA}$ to $8.410{\AA}$ with Cd concentration. The Mossbauer spectra for x<0.4 show a superposition of two sextets and a paramagnetic doublet at room temperature. The cation distribution for x=0 was determined to be $[Fe_{0.75}Al_{0.25}]^A[NiFe_{0.25}Al_{0.75}^BO_4$. The superparamagnetic doublet for x< 0.4 seems to be due to A1 ion in tetrahedral site by the superparamagnetic clustering effect.
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Hong, Kwang-Joon
- Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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- 2004.07a
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- pp.381-384
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- 2004
The stochiometric nix of evaporating materials for the $AgInS_2$ single crystal thin films were prepared from horizontal furnace. The polycrystal structure obtaind from the power x-ray diffraction was chalcopyrite. The lattice costants $a_0\;and\;c_0$ were $a_0=5.86(5.82)\;A,\;c_0=11.355(11.17)\;A$. To obtains the single crystal thin films, $AgInS_2$ mixed crystal were deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy(HWE) system. The temperates of the source and the substrate were $590^{\circ}C\;and\;450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time.
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