Abnormal spin-pumping effect at Pt/NiFe interface by an oxidation of ferromagnet

• Published in: Current applied physics Vol. 14; no. 12; pp. 1743 - 1747
• Main Authors: Kim, Sang-Il, Seo, Min-Su, Seo, Jung-Hye, Yun, Hyung Joong, Lee, Jouhahn, Choi, Yeon Suk, Park, Seung-young
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2014; 한국물리학회
• Subjects: Electric potential; Ferromagnetic resonance; Ferromagnetism; Intermetallics; Inverse spin Hall effect; Iron compounds; Nickel base alloys; Nickel compounds; Platinum; Spin pumping; Voltage; X-ray photoelectron spectroscopy; 물리학; Ferromagnetic resonance; Spin pumping; Inverse spin Hall effect; X-ray photoelectron spectroscopy
• ISSN: 1567-1739; 1878-1675; 1567-1739
• DOI: 10.1016/j.cap.2014.10.004

The Inverse Spin Hall Effect (ISHE) voltage induced by spin-pumping was measured in Pt/[nonoxidized or oxidized NiFe] samples. The spectrum shape of the DC voltage signal was well-reproduced by simple Lorentzian functions, which were consistent with the prediction of ISHE in Pt/nonoxidized NiFe sample. On the other hand, the voltage signal from the Pt/oxidized NiFe was significantly decreased in accordance with abnormal ferromagnetic resonance (FMR) behavior. The origin of the ISHE voltage degradation was investigated by the FMR spectrum and X-ray photoelectron spectroscopy (XPS) analyses. The spin-pumping was suppressed by the oxidation of NiFe layer and deficient Pt/NiFe interface. The well-defined ferromagnet and clear interface with a normal spin mixing conductance were experimentally demonstrated to be reasonable spin-pumping. •The ISHE voltage is measured in Pt/[nonoxidized or oxidized NiFe] samples.•The ISHE voltage from the Pt/oxidized NiFe is significantly decreased.•The spin-pumping effect is suppressed by the oxidation of Pt/NiFe interface.•The well-defined Pt/NiFe interface is demonstrated to be a reasonable spin-pumping.