The objective of this research is to carry out experiments to validate the current version of the SSE-based theory. The phonon-magnon coupling seems to be the most satisfying theory for the SSE at present. We will use LSMO which has high spin polarization to observe the SSE. Unlike previous observations where most experiments were focused on thin films, we will aim for the bulk form of LSMO. The size dependence of SSE will be tested. So the research in this proposed project will consist of 2 experimental sections.
1. An experiment will be set up to observe the SSE in LSMO. If the phonon-magnon coupling is responsible to the underlying physics of the SSE, the observed SSE signal in LSMO is expected to be large due to its high spin polarization. The Curie temperature of LSMO is closed to room temperature, approximately 350 K31; hence we may conduct the experiment through the critical temperature. Spin polarization of LSMO through the Curie temperature is different, so the SSE is expected to follow the same trend.
2. In literature, most research on SSE was focused on thin films setup, where the thickness of the sample is in a nanometre range. They have observed the spatial distribution of the SSE voltage signal. We want to confirm this effect by using bulk materials where we have higher degree of freedom to adjust the materials dimension and observe the effect more distinctly.
