• Journal of Magnetics
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• 제16권2호
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• pp.134-139
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• 2011

Magnetic properties of highly zinc-substituted manganese ferrites are discussed on the basis of cation distribution. High throughput neutron powder diffractometry indicates that the prepared samples possess a nearly normal spinel structure, where the substitution of nonmagnetic zinc ions mainly causes the dilution of magnetic ions in the A-sublattice and consequently affects bond-randomness in the B-sublattice. On the other hand, the estimated occupancy of manganese ions in the B site indicates that random anisotropy effects due to local Jahn-Teller distortions gradually weaken with the substitution. Bulk magnetometry indicates that the substitution smears the transition from a paramagnetic phase to a soft-magnetic phase. Furthermore, at lower temperatures, such a soft-magnetic phase is destabilized and a magnetic glassy state appears. These features of the magnetic properties of dilute spinel ferrites are discussed from the viewpoint of the above-mentioned various types of disorders.

• 한국결정성장학회지
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• 제8권2호
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• pp.278-285
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• 1998

$(A_{1-x}A^'_x)_2ZnCl_4$혼정에서 C-IC 상전이가 A' ions의 pinning 효과에 의해 x의 증가에 따라 사라지는 것은 알려져 왔다. 본 연구에서 우리는 C상에서 polarization 방향이 파괴되지 않고 IC상에서 long range ordering을 유지하는 새로운 혼정인 $K_2Zn_{1-X}Co_XCl_4$결정을 소개한다. 우리는 Czochralski법으로 여러비율에 대한 (x=0, 0.001, 0.005, 0.01, 0.1, 0.3, 0.5, 0.7, 1) $K_2Zn_{1-X}Co_XCl_4$혼정을 육성하였으며 육성된 결정의 성분분석, 열적분석 및 x에 따른 C-IC 상전이의 존재를 확인하였다.