Date: Tuesday, March 19, 2013
Time: 10:30 - 11:30
Place: 8F medium seminar room (room#811,812), Sengen
Transition metal pnictides such as MnSb have interesting magnetic and
magneto-transport properties and high potential in semiconductor
spintronics. I will discuss molecular beam epitaxy growth of these
materials on III-V semiconductor and Ge substrates, highlighting the
analogies with III-V epitaxy. We have recently grown thick (tens of nm)
epitaxial cubic polymorphs of MnSb on ordinary hexagonal MnSb, and the
experimental evidence for the cubic phase will be reviewed. We predict
cubic MnSb to be a robust half-metallic ferromagnet to beyond 300K, using
a "disordered local moments" density functional approach, which allows
non-zero temperature magnetic properties to be calculated from first
principles. This will be compared to the classic half-metal NiMnSb, which
probably loses its spin polarisation at much lower temperature.