| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
DD3, Spin Seebeck Effect in MnAs/GaMnAs Bilayers |
| Author(s) |
Kurtis Wickey, Christopher Jaworski, Jing Yang, Shawn Mack, David Awschalom, Joseph Heremans, Roberto Myers, Ezekiel Johnston-Halperin |
| On-Site Speaker (Planned) |
Kurtis Wickey |
| Abstract Scope |
A recently discovered thermo-transport phenomenon is the spin-Seebeck effect, which analogous to the charge Seebeck effect is a thermal redistribution of spin instead of electrons. First discovered by Uchida et al. in permalloy[1], subsequently in the ferromagnetic semiconductor GaMnAs [2], and the ferromagnetic insulator YIG [3], we observe it in the metallic ferromagnet MnAs and bilayer systems consisting of MnAs grown epitaxially on GaMnAs which results in an exchange bias of the GaMnAs layer[4]. A flux of spin-polarized particles induced by the temperature gradient enters the Pt strips deposited on the samples, where the inverse spin Hall effect converts it to a voltage signal that we measure. The voltage, and thus the spin polarization, are proportional to the temperature gradient. The temperature dependence of this voltage is studied above and below the Curie temperatures of GaMnAs and compared with SQUID measurements. MnAs and GaMnAs exhibit different coercivities and we are able to isolate and measure the spin-Seebeck signal due to each ferromagnetic layer. Their spin-Seebeck coefficients also have opposite polarities. We study the temperature dependence of the spin-Seebeck signal in MnAs and GaMnAs with a goal of better understanding the mechanism of the spin-Seebeck effect in these materials. This work was supported by the NSF and the ONR. |
| Proceedings Inclusion? |
Undecided |