Coupling phenomena in superconducting Nb/Fe multilayers
Coupling phenomena in superconducting Nb/Fe multilayers
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超导 Nb/Fe 多层膜中的耦合现象
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Y. Bruynseraede
中科院分区：
文献类型：
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作者：
G. Verbanck;C. Potter;V. Metlushko;R. Schad;V. Moshchalkov;Y. Bruynseraede
We measured the critical temperature ${T}_{c}$ and critical field ${H}_{c2}$ of molecular-beam epitaxy-grown Nb/Fe multilayers in which the layer thicknesses ${t}_{\mathrm{Fe}}$ and ${t}_{\mathrm{Nb}}$ are systematically varied. For constant ${t}_{\mathrm{Nb}}$ we observe a continuous decrease of ${T}_{c}$ with increasing ${t}_{\mathrm{Fe}}$ up to ${t}_{\mathrm{Fe}}=15\AA{}.$ At higher ${t}_{\mathrm{Fe}}$ values a sudden drop of ${T}_{c}$ is measured related to the onset of ferromagnetism in the Fe layers. Measurements of the shape and the angular dependence of ${H}_{c2}(T)$ clearly show that the superconducting Nb layers are already decoupled for ${t}_{\mathrm{Fe}}=12\AA{},$ magnetization measurements, however show that the Fe layers are ferromagnetic only for ${t}_{\mathrm{Fe}}g~16\AA{}.$ For constant ${t}_{\mathrm{Fe}}=25\AA{},$ the observed strong decrease of ${T}_{c}$ with decreasing Nb thickness as well as the temperature dependence of ${H}_{c2}$ are well described by the theoretical model for decoupled superconductor/ferromagnet multilayers.
We measured the critical temperature ${T}_{c}$ and critical field ${H}_{c2}$ of molecular-beam epitaxy-grown Nb/Fe multilayers in which the layer thicknesses ${t}_{\mathrm{Fe}}$ and ${t}_{\mathrm{Nb}}$ are systematically varied. For constant ${t}_{\mathrm{Nb}}$ we observe a continuous decrease of ${T}_{c}$ with increasing ${t}_{\mathrm{Fe}}$ up to ${t}_{\mathrm{Fe}}=15\AA{}.$ At higher ${t}_{\mathrm{Fe}}$ values a sudden drop of ${T}_{c}$ is measured related to the onset of ferromagnetism in the Fe layers. Measurements of the shape and the angular dependence of ${H}_{c2}(T)$ clearly show that the superconducting Nb layers are already decoupled for ${t}_{\mathrm{Fe}}=12\AA{},$ magnetization measurements, however show that the Fe layers are ferromagnetic only for ${t}_{\mathrm{Fe}}g~16\AA{}.$ For constant ${t}_{\mathrm{Fe}}=25\AA{},$ the observed strong decrease of ${T}_{c}$ with decreasing Nb thickness as well as the temperature dependence of ${H}_{c2}$ are well described by the theoretical model for decoupled superconductor/ferromagnet multilayers.