Phase transformations in Pt/Fe bilayers during post annealing probed by resistometry
Phase transformations in Pt/Fe bilayers during post annealing probed by resistometry
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DOI：
10.1088/1361-648x/ab169c
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
O. Shamis;N. Safonova;M. Voron;A. Burmak;S. I. Sidorenko;G. Katona;S. Gulyás;D. Beke;M. Albrecht;I. Vladymyrskyi
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文献类型：
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作者：
O. Shamis;N. Safonova;M. Voron;A. Burmak;S. I. Sidorenko;G. Katona;S. Gulyás;D. Beke;M. Albrecht;I. Vladymyrskyi
X射线衍射（XRD），二次中性质谱（SNMS）深度剖析，和电阻率测量被用来跟踪退火过程中的Pt/Fe双层薄膜的相变。最初，电阻率随着温度线性增加，直到150 °C，这是由于金属Pt和Fe双层的声子散射的贡献。进一步增加的退火温度导致一个陡峭的线性增加，这是与最初形成的化学无序的A1-相，随后形成的化学有序的L10-FePt相，证实了XRD和SNMS研究。最后，在约620 °C下，在整个膜中形成单一的L10-FePt相。此外，电阻率还包含对总电阻率的磁贡献。在这种情况下，磁序的损失由电阻率在约310 °C下的温度依赖性的变化来指示，所述温度代表初始形成的Al-FePt合金的居里温度，而最终形成的LlO-FePt合金显示出约410 °C的更高的磁转变温度。在这项研究中，它已被证明，电阻结合结构和化学分析提供了有价值的信息扩散过程中，结构相的形成及其稳定范围，以及在磁性转变温度。
X-ray diffraction (XRD), secondary neutral mass spectrometry (SNMS) depth profiling, and electrical resistivity measurements were used to follow the phase transformations in Pt/Fe bi-layered thin films during annealing. Initially, the electrical resistivity increases linearly with temperature up to 150 °C due to the contribution of phonon scattering of the metallic Pt and Fe bilayer. Further increase of the annealing temperature leads to a steeper linear increase, which is associated with the initial formation of the chemically disordered A1-phase followed by the formation of the chemically ordered L10-FePt phase, as confirmed by XRD and SNMS studies. Finally, at about 620 °C the single L10-FePt phase has formed throughout the film. Moreover, the electrical resistivity contains also the magnetic contribution to the total resistivity. In this case, the loss in magnetic order is indicated by a change in temperature dependence of the resistivity at about 310 °C, representing the Curie temperature of the initially formed A1-FePt alloy, while the finally formed L10-FePt alloy reveals a higher magnetic transition temperature of about 410 °C. In this study, it has been demonstrated that resistometry in combination with structural and chemical analysis provides valuable information on diffusion processes, structural phase formations and its stability range, as well as on the magnetic transition temperature.