Magnetoresistive measurement of the exchange constant in permalloy
Magnetoresistive measurement of the exchange constant in permalloy
复制标题
坡莫合金中交换常数的磁阻测量
DOI：
10.1109/tmag.1987.1065345
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发表时间：
1987
影响因子：
2.1
通讯作者：
D. Latourette
中科院分区：
文献类型：
--
作者：
N. Smith;W. Doyle;D. Markham;D. Latourette
电流通过沿磁条(容易)轴磁化的细铁磁条，将产生一个内部磁场，该内部磁场试图通过薄膜厚度以相反的方向扇形磁化，但这与交换力相反。Methfessel等人的研究。用感应法在坡莫合金中实验观察了这一效应，并确定了交换常数A的值为0.55×10-6ergs/cm。这大约是通常使用自旋波共振测得的值的一半。我们扩展了理论分析，并用直流磁阻检测代替感应对3000 A厚的坡莫合金小条纹进行了重复实验。通过比较理论和实验结果，我们确定了A值为1.1×10-6erg/cm±10%。不需要关于表面各向异性或磁化不均匀的假设，这是解释自旋波模式所必需的。我们相信这是在坡莫合金中报道的A的最可靠的值。
A current passed through a thin ferromagnetic stripe, with magnetization along the stripe (easy) axis, will generate an internal field that tries to fan the magnetization in opposite directions through the film thickness, but which is opposed by exchange forces. Methfessel et al. observed this effect experimentally in Permalloy using inductive methods and determined a value for A, the exchange constant, of 0.55 × 10-6ergs/cm. This is about half the value normally measured using spin wave resonance. We have extended the theoretical analysis and repeated the experiment on small, 3000 A thick Permalloy stripes using dc magnetoresistive detection instead of induction. By comparing theoretical and experimental results, we have determined a value for A of 1.1 × 10-6erg/cm ± 10%. No assumptions about surface anisotropy or magnetization inhomogenieties, required to explain spin wave modes, are needed. We believe this is the most reliable value reported for A in Permalloy.