Band structure of strained Gd(0001) films

Abstract

The electronic structure of strained and unstrained Gd͑0001͒ surfaces has been studied both theoretically and experimentally with spin-polarized photoemission spectroscopy and spin-polarized inverse photoemission spectroscopy. Good agreement between calculated surface bands and surface-induced features of the spectra provides the basis for a more detailed explanation of the origin of the spin-polarized bands than was previously possible. It has been found that observed relaxation of the expansively strained in-plane crystal lattice constant, of Gd͑0001͒ on Mo͑112͒, significantly affects the electronic structure of the surface.

Strain Induced Half-Metal to Semiconductor Transition in GdN

“…An accurate description of the electronic structure of rare-earth compounds is a very challenging problem because of their unfilled 4f shells [9]. Calculations based on local spin density approximation (LSDA) are well known to underestimate the band gap in semiconductors.…”

Are half-metallic ferromagnets half metals? (invited)

“…The 96 A band structure like that of gadolinium, with a strong magnetic surface state near the Fermi energy at ⌫ , might appear to be a very high polarization ferromagnet, if such measurements are taken at only one wave vector near the surface Brillouin zone center, [97][98][99] well below the Debye temperature. 99 No one would argue that gadolinium is a half-metallic system.…”

Electronic, Magnetic and Transport Properties of Rare‐Earth Monopnictides

“…Rare-earth systems are known to exhibit band-and wavevector-dependent exchange splitting [9,11,150,151]. Taking GdN as an example, we see that the Gd 5d states are polarized by the 4f majority states, due to exchange interactions and 4f-5d orthogonality.…”

“…From the analysis of these data, Duan et al [89] proposed an expression for the superexchange interaction: (11) where Δ is the energy difference between the rare-earth 5d orbital and the outmost p state of the pnictogen ion, n d is the induced d moment on the rare-earth atom due to atomic 4f-5d exchange interactions, and the hopping parameter t pd can be evaluated according to Figure 15. Calculated exchange parameters J 1 (a) and J 2 (b) for Gd pnictides as a function of the lattice strain: GdN (circles), GdP (stars), GdAs (diamonds), GdSb (squares), GdBi (triangles).…”

“…This changing 4f occupation means that the rare-earth elements and their compounds have a wide range of different magnetic properties and electronic structures. Due to the unfi lled 4f shells of rare-earth atoms, it is a challenging problem to obtain an accurate theoretical description of the electronic structure of rare-earth compounds [11]. In spite of the fact that the 4f energy levels often overlap with the non-4f broad bands of the system, they generally form very narrow resonances, and are often treated as core states in the theoretical efforts.…”