Tan Ling, Wang Lei, Min Tai
Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University Xi'an Shaanxi 710049 China
RSC Adv. 2019 Dec 12;9(70):41099-41106. doi: 10.1039/c9ra08541f. eCollection 2019 Dec 9.
The magnetic states of one single atomic layer of iron epitaxially grown on 4d and 5d nonmagnetic metals are studied under strain systematically using first principle calculations. Our results show that, without strain, the iron on top of different 4d and 5d nonmagnetic metals shows distinct antiferromagnetic or ferromagnetic ground states: a parallel antiferromagnetic ground state (p-AFM) on Rh and a central antiferromagnetic ground state (c-AFM) on Ir and ferromagnetic (FM) ground state on Pd, Ag, Pt and Au. However, when introducing in-plane biaxial and uniaxial strain (Δ ) on the substrates, the ground state of iron can be manipulated easily. In detail, for biaxial strain, the ground state of iron on an Rh substrate becomes FM when Δ < -2.0% and c-AFM when Δ > 0.8%, and on an Ir substrate, the ground state of iron becomes FM when Δ < -2.8% and c-AFM when Δ > -0.8%. However, for the uniaxial strain along the direction, while using the corresponding Poisson's ratios to determine the strain along the direction, the ground state of iron on an Rh substrate remains the p-AFM state, but on an Ir substrate, the ground state of iron changes from c-AFM to p-AFM at Δ = 0.2% or Δ = -0.3% along the direction respectively.
利用第一性原理计算系统地研究了外延生长在4d和5d非磁性金属上的单层铁原子的磁态。我们的结果表明，在无应变情况下，不同4d和5d非磁性金属上的铁呈现出不同的反铁磁或铁磁基态：Rh上为平行反铁磁基态（p-AFM），Ir上为中心反铁磁基态（c-AFM），Pd、Ag、Pt和Au上为铁磁（FM）基态。然而，当在衬底上引入面内双轴和单轴应变（Δ ）时，铁的基态可以很容易地被调控。具体而言，对于双轴应变，当Δ < -2.0%时，Rh衬底上铁的基态变为FM，当Δ > 0.8%时变为c-AFM；在Ir衬底上，当Δ < -2.8%时铁的基态变为FM，当Δ > -0.8%时变为c-AFM。然而，对于沿 方向的单轴应变，在使用相应的泊松比来确定沿 方向的应变时，Rh衬底上铁的基态保持p-AFM态，但在Ir衬底上，铁的基态在沿 方向分别为Δ = 0.2%或Δ = -0.3%时从c-AFM变为p-AFM。
