科技报告详细信息
Composition dependence of the spin wave stiffness parameter in La(sub 1-x)Ca(sub x)MnO(sub 3) CMR materials. | |
Rhyne, J. J. ; Kaiser, H. ; Stumpe, L. ; Mitchell, J. F. ; Mccloskey, T. ; Chourasia, A. R. | |
Technical Information Center Oak Ridge Tennessee | |
关键词: Spin waves; Lanthanum oxides; Calcium oxides; Magnetic materials; Chemical composition; | |
RP-ID : DE2001757538 | |
学科分类:工程和技术(综合) | |
美国|英语 | |
来源: National Technical Reports Library | |
【 摘 要 】
Long wavelength spin waves in La(1-x)Ca(x)MnO(3)CMR materials exhibit conventional Heisenberg dispersion (E = D1(sup 2) + delta), but with an anomalous temperature dependence for the spin dispersion parameter D. For x approx. 0.33, near the optimum CMR composition, D remains approximately 50% of its T = 0K value before exhibiting a near-first-order transition at T(sub c), instead of following the expected power law decrease as T approaches T(sub c-). No temperature hysteresis was observed in either D or in the magnetization. Compositions with x = 0.40 and 0.45 show more conventional temperature renormalization.
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