Damping of ferromagnetic resonance in NiFe alloys

Abstract

From linewidth data of bulk (110) NiFe alloy single crystals (100 to 45 wt% Ni) at 19.5 and 26 GHz Landau‐Lifshits damping parameters were derived, which, except for 100% Ni, increase with temperature between — 196 °C and the Curie point. The λ values of the alloys are found to be considerably lower than for pure Ni. For 75% Ni, λ shows a very pronounced decrease with increasing degree of order. The λ dependence on frequency, temperature, alloy composition, and state of order is in qualitative agreement with a relaxation model on the basis of spin—orbit effects within a band picture proposed by Kamberský.

Long-Lived Ultrafast Spin Precession in Manganese Alloys Films with a Large Perpendicular Magnetic Anisotropy

“…The eff values reported here approximate values for materials with weak magnetic anisotropy, i.e., Fe, Co, and Ni [7] [dashed lines in Fig. 2(e)].…”

“…In the simplest expression, $ ½ 2 B DðE F Þ=M S ð=WÞ 2 = E , where DðE F Þ is the density of states at the Fermi level E F , the SO interaction energy, W the d-band width, and 1= E the electron scattering frequency [5,6]. Subsequent experiments have supported the above relation for qualitatively in soft magnetic alloys [7][8][9]. A quantitative theory has been developed based on the torque-correlation model [6] using first-principles band structure calculations that predicted the correct orders of magnitude for of Fe, Co, and Ni [10] and demonstrated the influence of density of states on in half-metallic magnets [9,11].…”

“…The open (filled) circles correspond to the data for ¼ 1:46 (0.88).The solid curves through data points are model fits. The dashed lines in (e) show typical damping constants for Fe, Co, and Ni[7].…”

Spin pumping and spin transfer

“…In spite of a large spread in measured values, these seem to be systematically larger than the calculated values. Part of this discrepancy can be attributed to an increase in α with temperature 122,134 .…”

Unified First-Principles Study of Gilbert Damping, Spin-Flip Diffusion, and Resistivity in Transition Metal Alloys

“…In spite of a large spread in measured values, these seem to be systematically larger than the calculated values. Part of this discrepancy can be attributed to an increase in α with temperature [22,25].…”