Conductivitylike Gilbert Damping due to Intraband Scattering in Epitaxial Iron.

Confirming the origin of Gilbert damping by experiment has remained a challenge for many decades, even for simple ferromagnetic metals. Here, we experimentally identify Gilbert damping that increases with decreasing electronic scattering in epitaxial thin films of pure Fe. This observation of conductivitylike damping, which cannot be accounted for by classical eddy-current loss, is in excellent quantitative agreement with theoretical predictions of Gilbert damping due to intraband scattering. Our results resolve the long-standing question about a fundamental damping mechanism and offer hints for engineering low-loss magnetic metals for cryogenic spintronics and quantum devices.

[1]  D. Vanderbilt,et al.  Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. , 1990, Physical review. B, Condensed matter.

[2]  W. Kwok,et al.  Strong Coupling between Magnons and Microwave Photons in On-Chip Ferromagnet-Superconductor Thin-Film Devices. , 2019, Physical review letters.

[3]  W. Kwok,et al.  Strong Coupling between Magnons and Microwave Photons in On-Chip Ferromagnet-Superconductor Thin-Film Devices. , 2019, Physical review letters.

[4]  T. A. Ohki,et al.  A cryogenic spin-torque memory element with precessional magnetization dynamics , 2019, Scientific Reports.

[5]  P. Le Fèvre,et al.  Polycrystalline Co2Mn-based Heusler thin films with high spin polarization and low magnetic damping , 2019, Applied Physics Letters.

[6]  V. Kamberský.  On the Landau-Lifshitz relaxation in ferromagnetic metals , 1970 .

[7]  T. Mewes,et al.  Bulk Single Crystal‐Like Structural and Magnetic Characteristics of Epitaxial Spinel Ferrite Thin Films with Elimination of Antiphase Boundaries , 2017, Advanced materials.

[8]  D. Ralph,et al.  Spin transfer torques , 2007, 0711.4608.

[9]  E. Sonin.  Spin currents and spin superfluidity , 2008, 0807.2524.

[10]  B. Heinrich,et al.  Ferromagnetic antiresonance transmission through pure iron at 73 GHz , 1988 .

[11]  S. Wimmer,et al.  Emergence of anisotropic Gilbert damping in ultrathin Fe layers on GaAs(001) , 2018 .

[12]  D. McComb,et al.  Metallic ferromagnetic films with magnetic damping under 1.4 × 10−3 , 2017, Nature Communications.

[13]  Yanli Wang,et al.  Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials , 2009 .

[14]  M. Stiles,et al.  Anisotropic damping of the magnetization dynamics in Ni, Co, and Fe , 2010 .

[15]  R. Victora,et al.  Dependence of Kambersky damping on Fermi level and spin orientation , 2014 .

[16]  Y3Fe5O12 spin pumping for quantitative understanding of pure spin transport and spin Hall effect in a broad range of materials (invited) , 2014, 1410.1597.

[17]  P. Bortolotti,et al.  Inverse Spin Hall Effect in nanometer-thick YIG/Pt system , 2013 .

[18]  M. Cinal,et al.  Calculation of Gilbert damping in ferromagnetic films , 2013 .

[19]  Jan Dellith,et al.  Sub-micrometer yttrium iron garnet LPE films with low ferromagnetic resonance losses , 2016, 1608.08043.

[20]  J. Ferré,et al.  Domain wall mobility, stability and Walker breakdown in magnetic nanowires , 2007, cond-mat/0702492.

[21]  D. Edwards,et al.  The absence of intraband scattering in a consistent theory of Gilbert damping in pure metallic ferromagnets , 2015, Journal of physics. Condensed matter : an Institute of Physics journal.

[22]  P. Kelly,et al.  Unified first-principles study of gilbert damping, spin-flip diffusion, and resistivity in transition metal alloys. , 2010, Physical review letters.

[23]  Z. Valy Vardeny,et al.  Organic-based magnon spintronics , 2018, Nature Materials.

[24]  C. Back,et al.  Magnetic damping: domain wall dynamics versus local ferromagnetic resonance. , 2014, Physical review letters.

[25]  Luqiao Liu,et al.  Strong Coupling between Microwave Photons and Nanomagnet Magnons. , 2019, Physical review letters.

[26]  Zhe Yuan,et al.  First-principles calculations of magnetization relaxation in pure Fe, Co, and Ni with frozen thermal lattice disorder , 2011, 1102.5305.

[27]  M. Farle.  Ferromagnetic resonance of ultrathin metallic layers , 1998 .

[28]  R. McMichael,et al.  Classical model of extrinsic ferromagnetic resonance linewidth in ultrathin films , 2004, IEEE Transactions on Magnetics.

[29]  Heiko Wende,et al.  Two-magnon scattering and viscous Gilbert damping in ultrathin ferromagnets , 2006 .

[30]  I. Barsukov,et al.  Low relaxation rate in epitaxial vanadium-doped ultrathin iron films. , 2007, Physical review letters.

[31]  Lijun Zhu,et al.  Cryogenic Memory Architecture Integrating Spin Hall Effect based Magnetic Memory and Superconductive Cryotron Devices , 2019, Scientific Reports.

[32]  B. Heinrich,et al.  Temperature dependence of the Landau–Lifshitz damping parameter for iron , 1991 .

[33]  N. Kioussis,et al.  Intrinsic Damping Phenomena from Quantum to Classical Magnets: An ab-initio Study of Gilbert Damping in Pt/Co Bilayer. , 2017, 1709.04911.

[34]  B. Heinrich,et al.  Wave number and temperature dependent Landau‐Lifshitz damping in nickel , 1979 .

[35]  Wei Zhang,et al.  Giant Anisotropy of Gilbert Damping in Epitaxial CoFe Films. , 2019, Physical review letters.

[36]  T. Miyazaki,et al.  Low damping constant for Co2FeAl Heusler alloy films and its correlation with density of states , 2009 .

[37]  Yasuo Ando,et al.  Magnetic Damping in Ferromagnetic Thin Films , 2006 .

[38]  M D Stiles,et al.  Identification of the dominant precession-damping mechanism in Fe, Co, and Ni by first-principles calculations. , 2007, Physical review letters.

[39]  Precession damping in itinerant ferromagnets , 2007 .

[40]  G. Woltersdorf,et al.  Two-magnon scattering in a self-assembled nanoscale network of misfit dislocations , 2004 .

[41]  A. Chumak.  Magnon Spintronics , 2019, Spintronics Handbook: Spin Transport and Magnetism, Second Edition.

[42]  G. Woltersdorf,et al.  First-principles calculation of the Gilbert damping parameter via the linear response formalism with application to magnetic transition metals and alloys , 2013, 1301.2114.

[43]  R. Lukaszew.  Relaxation in Magnetic Materials for Spintronics , 2015 .

[44]  Claudia Mewes,et al.  Origin of low Gilbert damping in half metals , 2009 .

[45]  S. M. Bhagat,et al.  Temperature variation of ferromagnetic relaxation in the 3 d transition metals , 1974 .

[46]  R. McMichael.  A mean-field model of extrinsic line broadening in ferromagnetic resonance , 2008 .

[47]  C. Mewes,et al.  Relaxation in Magnetic Materials for Spintronics , 2015 .

[48]  C. Back,et al.  Magnetic damping in poly-crystalline Co25Fe75: Ferromagnetic resonance vs. spin wave propagation experiments , 2017 .

[49]  P. Li,et al.  Nanometer-Thick Yttrium Iron Garnet Films With Extremely Low Damping , 2014, IEEE Magnetics Letters.

[50]  H. Monkhorst,et al.  SPECIAL POINTS FOR BRILLOUIN-ZONE INTEGRATIONS , 1976 .

[51]  J. Lock.  Eddy current damping in thin metallic ferromagnetic films , 1966 .

[52]  H. Hwang,et al.  Ultralow Damping in Nanometer-Thick Epitaxial Spinel Ferrite Thin Films. , 2018, Nano letters.

[53]  Gerhard Jakob,et al.  Pulsed laser deposition of epitaxial yttrium iron garnet films with low Gilbert damping and bulk-like magnetization , 2014 .

[54]  V. Cros,et al.  Ultra-low damping insulating magnetic thin films get perpendicular , 2018, Nature Communications.

[55]  V. Kamberský.  On ferromagnetic resonance damping in metals , 1976 .

[56]  G. Scuseria,et al.  Restoring the density-gradient expansion for exchange in solids and surfaces. , 2007, Physical review letters.

[57]  K. Temst,et al.  Electric transport properties of epitaxial Fe and Cr films with very low intralayer scattering , 1998 .

[58]  Michael L. Schneider,et al.  Ultra-low magnetic damping of a metallic ferromagnet , 2016 .

[59]  R. Arias,et al.  Extrinsic contributions to the ferromagnetic resonance response of ultrathin films , 1999 .

[60]  Shiming Zhou,et al.  Role of antisite disorder on intrinsic Gilbert damping in L 1 0 FePt films , 2015 .

[61]  H. Ohno,et al.  Current-induced torques in magnetic materials. , 2012, Nature materials.

[62]  Inhomogeneous Broadening of Ferromagnetic Resonance Lines , 1969 .

[63]  T. Silva,et al.  Magnetic properties in ultrathin 3d transition-metal binary alloys. II. Experimental verification of quantitative theories of damping and spin pumping , 2017, 1701.02475.

[64]  Erol Girt,et al.  Spin dynamics and magnetic anisotropies at the Fe/GaAs(001) interface , 2011 .

[65]  Z. Frait,et al.  Temperature Dependence of the FMR Linewidth of Iron Single-Crystal Platelets , 1966 .

[66]  Low damping in epitaxial sputtered iron films , 2006 .

[67]  G. Schmidt,et al.  Yttrium Iron Garnet Thin Films with Very Low Damping Obtained by Recrystallization of Amorphous Material , 2016, Scientific Reports.

[68]  J. Garay,et al.  Exquisite growth control and magnetic properties of yttrium iron garnet thin films , 2016 .

[69]  J. Ghanbaja,et al.  Ultralow Magnetic Damping in Co2Mn -Based Heusler Compounds: Promising Materials for Spintronics , 2019, Physical Review Applied.

[70]  A. D. Corso.  Pseudopotentials periodic table: From H to Pu , 2014 .

[71]  B. Heinrich.  Spin Relaxation in Magnetic Metallic Layers and Multilayers , 2005 .