Browsing by Author "Klewe, Christoph"

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    Evidence of dynamical effects and critical field in a cobalt spin crossover complex
    (Royal Society of Chemistry, 2022-01) Ekanayaka, Thilini K.; Wang, Ping; Yazdani, Saeed; Phillips, Jared Paul; Mishra, Esha; Dale, Ashley S.; N'Diaye, Alpha T.; Klewe, Christoph; Shafer, Padraic; Freeland, John; Streubel, Robert; Wampler, James Paris; Zapf, Vivien; Cheng, Ruihua; Shatruk, Michael; Dowben, Peter A.; Physics, School of Science
    The [Co(SQ)2(4-CN-py)2] complex exhibits dynamical effects over a wide range of temperature. The orbital moment, determined by X-ray magnetic circular dichroism (XMCD) with decreasing applied magnetic field, indicates a nonzero critical field for net alignment of magnetic moments, an effect not seen with the spin moment of [Co(SQ)2(4-CN-py)2].
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    Suppression of spin pumping at metal interfaces
    (AIP, 2023-10) Lim, Youngmin; Nepal, Bhuwan; Smith, David A.; Wu, Shuang; Srivastava, Abhishek; Nakarmi, Prabandha; Mewes, Claudia; Jiang, Zijian; Gupta, Adbhut; Viehland, Dwight D.; Klewe, Christoph; Shafer, Padraic; Park, In Jun; Mabe, Timothy; Amin, Vivek P.; Heremans, Jean J.; Mewes, Tim; Emori, Satoru; Physics, School of Science
    An electrically conductive metal typically transmits or absorbs a spin current. Here, we report on evidence that interfacing two metal thin films can suppress spin transmission and absorption. We examine spin pumping in spin-source/spacer/spin-sink heterostructures, where the spacer consists of metallic Cu and Cr thin films. The Cu/Cr spacer largely suppresses spin pumping—i.e., neither transmitting nor absorbing a significant amount of spin current—even though Cu or Cr alone transmits a sizable spin current. The antiferromagnetism of Cr is not essential for the suppression of spin pumping, as we observe similar suppression with Cu/V spacers with V as a nonmagnetic analog of Cr. We speculate that diverse combinations of spin-transparent metals may form interfaces that suppress spin pumping, although the underlying mechanism remains unclear. Our work may stimulate a new perspective on spin transport in metallic multilayers.