Spin lattice relaxation of 8Li in a ferromagnetic EuO epitaxial thin film

β-detected NMR spin relaxation in a thin film heterostructure of ferromagnetic EuO

“…Qualitatively, the fraction that disappears at early times is consistent with 8 Li in the EuO layer, where one expects fast relaxation due to dynamics of the Eu spins. The assignment of this fraction to the EuO layer is also consistent with the implantation energy dependence measured by varying the bias voltage at low temperature [24] that showed this signal to be maximized near 18 keV. The inset of Fig.…”

“…While the simulated implantation profile does not admit a quantitative identification of the two signals, the temperature dependence λ(T ) provides another way to distinguish between them. While the relaxation in LAO has been measured at low magnetic fields [23], the high field relaxation is substantially slower, as evident at higher implantation energy in the present sample [24], but its T dependence is not known. On the other hand, the Korringa relaxation is known in Au [43].…”

“…The sample is the same (and the data taken at the same time) as in Ref. [24]. The intrinsic magnetic easy axis for EuO is along [111] [13], but for a thin film, shape anisotropy reorients it into the plane.…”

“…We recall that attempts to observe the β-NMR resonance were unsuccessful [24], likely because it was too broad for the limited rf power, but it may also have been strongly shifted by a large static internal field. We note that the implanted interstitial μ + experiences an internal field of about 0.2 T at low T in EuO [9,11].…”

Thickness-dependent magnetic properties of oxygen-deficient EuO

“…2). Signatures of a modified surface electronic structure have been reported previously for EuO bulk crystals [25,26] and possibly thin films [27]. Direct experimental evidence for a significant upward band bending at the Pt-EuO 1−x interface can, however, be seen in the temperature dependence of the magnetization shown in the inset of Fig.…”