CoO‐NiO superlattices: Interlayer interactions and exchange anisotropy with Ni81Fe19 (invited)
CoO‐NiO superlattices: Interlayer interactions and exchange anisotropy with Ni81Fe19 (invited)
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CoO-NiO超晶格：与Ni81Fe19的层间相互作用和交换各向异性（特邀）
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
A. Berkowitz
中科院分区：
文献类型：
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作者：
M. Carey;A. Berkowitz
在多晶反铁磁CoO-NiO薄膜超晶格中观察到强烈的层间交换相互作用。这是确定通过测量交换场H e耦合这些超晶格与Ni 81 Fe 19。在该温度以上，H e为零（阻断温度）被视为超晶格的有序温度的量度。在具有短重复距离的CoO-NiO超晶格中，CoO和NiO层在单一温度下有序，该温度介于体CoO和NiO的有序温度之间。这些有序化温度与具有相同总组成的Co x Ni 1 −x O合金膜相同。的温度依赖性的H e在一些超晶格交换偶偏离预期的立方反铁磁体的线性行为。此外，一些CoO-NiO超晶格引起的交换各向异性大于CoxNi 1-xO引起的交换各向异性。较高的H e和非线性温度依赖性表明，层间耦合对超晶格内各层的磁晶各向异性有很强的影响。制备厚NiO/薄CoO/Ni 81 Fe 19三层以研究氧化物-氧化物相互作用的厚度依赖性。当CoO层足够薄（≤20 A）时，CoO有序化温度接近NiO值，表明整个CoO层中有相当强的耦合。对于较厚的CoO层（≥30 A），耦合的影响弱得多。
A strong interlayer exchange interaction is observed in polycrystallineantiferromagnetic CoO‐NiO thin‐film superlattices. This was determined by measuring the exchange field H e resulting from coupling these superlattices with Ni81Fe19. The temperature above which H e is zero (the blocking temperature) is taken as a measure of the ordering temperature of the superlattice. In CoO‐NiO superlattices with short repeat distances the CoO and NiO layers order at a single temperature that is between the ordering temperatures of bulk CoO and NiO. These ordering temperatures are the same as for Co x Ni1−x O alloy films with the same overall composition. The temperature dependence of H e in some of the superlattice exchange couples deviates from the linear behavior expected for cubic antiferromagnets. In addition, the exchange anisotropy induced by some CoO‐NiO superlattices is greater than that induced by Co x Ni1−x O. The higher H e and nonlinear temperature dependence suggest that the interlayer coupling has a strong effect on the magnetocrystalline anisotropy of the layers within the superlattice. Thick‐NiO/thin‐CoO/Ni81Fe19trilayers were produced to investigate the thickness dependence of the oxide‐oxide interaction. When the CoO layers are sufficiently thin (≤20 A), the CoO ordering temperature approximates the NiO value, indicating quite strong coupling throughout the CoO layer. The effect of the coupling is much weaker for thicker CoO layers (≥30 A).