L10 FePt films were deposited on MgO (001) substrates heated to 700°C by magnetron sputtering.Assisted by the misfit of lattice between film and substrate,strong (001) texture was formed.The film at nominal thick...L10 FePt films were deposited on MgO (001) substrates heated to 700°C by magnetron sputtering.Assisted by the misfit of lattice between film and substrate,strong (001) texture was formed.The film at nominal thickness t N=5 nm was composed of nanoparticles with a size of～70 nm,and showed a high coercivity of～105 kOe at 4.2 K.At t N=～50 nm,as the film changed from discontinuous to continuous,the coercivity dropped about one order of magnitude.Micromagnetic simulation implies that the magnetization reversal is a vortex-like nuclear type.The ideal coercivity of a separated single-domain L10 FePt nanoparticle with a size of 70 nm×70 nm×5 nm is～121 kOe.This tells us that the experimental coercivity has nearly reached the limit of ideal single crystalline nanoparticles.展开更多
基金supported by Chongqing Natural Science Foundation(Grant No.CSTC2009BB8102)Southwest University Doctorial Foundation (Grant No.SWUB2006031)
文摘L10 FePt films were deposited on MgO (001) substrates heated to 700°C by magnetron sputtering.Assisted by the misfit of lattice between film and substrate,strong (001) texture was formed.The film at nominal thickness t N=5 nm was composed of nanoparticles with a size of～70 nm,and showed a high coercivity of～105 kOe at 4.2 K.At t N=～50 nm,as the film changed from discontinuous to continuous,the coercivity dropped about one order of magnitude.Micromagnetic simulation implies that the magnetization reversal is a vortex-like nuclear type.The ideal coercivity of a separated single-domain L10 FePt nanoparticle with a size of 70 nm×70 nm×5 nm is～121 kOe.This tells us that the experimental coercivity has nearly reached the limit of ideal single crystalline nanoparticles.
