Magnon-phonon hybridization in nearly compensated magnets for thermoelecric conversion and heat control

2020 Fiscal Year Annual Research Report

• Project/Area Number: 20K05297
• Research Institution: Tohoku University
• Principal Investigator: RAMOS Rafael 東北大学, 材料科学高等研究所, 助教 (40839312)
• Project Period (FY): 2020-04-01 – 2021-03-31
• Keywords: Spintronics / Magnons / Phonons / spin Seebeck / magnetic compensation

Outline of Annual Research Achievements

The project deals with the investigation of spin-lattice interaction effects in magnetic insulators, in particular the effect of magnetic compensation on spin-heat conversion (spin Seebeck effect: SSE) in Ga-substituted yttrium iron garnet (Ga-YIG), with increasing Ga-substitution the magnetic compensation increases.
I optimized the growth of high-quality Ga-YIG by liquid phase epitaxy, the structural quality was confirmed by x-ray diffraction. The presence of peaks in the SSE voltage at lower magnetic field than in YIG confirm the larger compensation and high magnetic quality of the films.
Further spin transport studies on the grown films are to be performed to investigate the role of magnetic compensation on magnon-phonon hybridization and its effect on the spin-heat conversion properties.

Research Products

• [Journal Article] Efficient Spin Torques in Antiferromagnetic CoO/Pt Quantified by Comparing Field- and Current-Induced Switching (2020)
  • Author(s): L. Baldrati, C. Schmitt, O. Gomonay, R. Lebrun, R. Ramos, E. Saitoh, J. Sinova, M. Klaui
  • Journal Title: Physical Review Letters Volume: 125 Pages: 077201
  • DOI: 10.1103/PhysRevLett.125.077201
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Concurrent magneto-optical imaging and magneto-transport readout of electrical switching of insulating antiferromagnetic thin films (2020)
  • Author(s): F. Schreiber, L. Baldrati, C. Schmitt, R. Ramos, E. Saitoh, R. Lebrun, M. Klaui
  • Journal Title: Applied Physics Letters Volume: 117 Pages: 082401
  • DOI: 10.1063/5.0011852
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Identification of Neel vector orientation in antiferromagnetic domains switched by currents in NiO/Pt thin films (2020)
  • Author(s): C. Schmitt, L. Baldrati, L. Sanchez-Tejerina, F. Schreiber, A. Ross, M. Filianina, S. Ding, F. Fuhrmann, R. Ramos, F. Maccherozzi, D. Backes, E. Saitoh, G. Finocchio, M. Klaui
  • Journal Title: arXiv Volume: 2008.08507 Pages: -
  • Int'l Joint Research
• [Journal Article] Direct imaging of current-induced antiferromagnetic switching revealing a pure thermomagnetoelastic switching mechanism (2020)
  • Author(s): H. Meer, F. Schreiber, C. Schmitt, R. Ramos, E. Saitoh, O. Gomonay, J. Sinova, L. Baldrati, M. Klaui
  • Journal Title: arXiv Volume: 2008.05219 Pages: -
  • Int'l Joint Research
• [Journal Article] Observation of quantum interference conductance fluctuations in metal rings with strong spin-orbit coupling (2020)
  • Author(s): R. Ramos, T. Makiuchi, T. Kikkawa, S. Daimon, K. Oyanagi, E. Saitoh
  • Journal Title: arXiv Volume: 2010.01300 Pages: -