11:15 AM - 11:30 AM
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[19a-D104-9] The Spin Polarized Electronic Structure of
Metal Overlayers on Magneto-Electric Cr2O3
Keywords:electronic structure, megneto-electric materila, spin polarized photoemission
Perpendicular exchange-bias structures, based on the antiferromagnetic and magneto-electric Cr2O3(0001), have drawn considerable attention, in part because of potential applications in voltage controlled spintronics. The boundary spin polarization at the surface of the magnetoelectric Cr2O3(0001), can be isothermally voltage-controlled to provide perpendicular voltage-controlled exchange-bias in an adjacent ferromagnet [1,2]. This means that the adjacent ferromagnet is typically chosen with perpendicular magnetic anisotropy, e.g. Co-Pd or Co-Pt multilayers. Recently, scalable magneto-electric magnetic random access memory, based on the anomalous Hall effect that occurs in Pt overlayers on Cr2O3 has been proposed [3,4]. But this latter memory device concept depends on an induced polarization in the Pd or Pt overlayer on Cr2O3(0001).
In this presentation, we illustrate the induced polarization in several different overlayers, such as Pt, Pb, and Co, on the top of Cr2O3(0001). The interaction between the Cr2O3(0001) surface and an overlayer can be quite complex [5,6]. For example, we were recently able to show that the antiferromagnetic exchange coupling between the surface Cr ions of magneto-electric Cr2O3(0001) and Co atoms in an overlayer, shows significant canting, as seen in Figure 1, and demonstrated by spin polarized photoemission in Figure 2.
In this presentation, we illustrate the induced polarization in several different overlayers, such as Pt, Pb, and Co, on the top of Cr2O3(0001). The interaction between the Cr2O3(0001) surface and an overlayer can be quite complex [5,6]. For example, we were recently able to show that the antiferromagnetic exchange coupling between the surface Cr ions of magneto-electric Cr2O3(0001) and Co atoms in an overlayer, shows significant canting, as seen in Figure 1, and demonstrated by spin polarized photoemission in Figure 2.