Intikhab Ulfat

Thermal diffusion of Mn through GaAs overlayers on (Ga, Mn)As.

Thermally stimulated diffusion of Mn through thin layers of GaAs has been studied by x-ray photoemission. (Ga, Mn)As samples with 5 at% Mn were capped with 4, 6 and 8 monolayer (ML) GaAs, and Mn diffusing through the GaAs was trapped on the surface by means of amorphous As. It was found that the out-diffusion is completely suppressed for an 8 ML thick GaAs film. The short diffusion length is attributed to an electrostatic barrier formed at the (Ga, Mn)As/GaAs interface.

Pseudogap behavior in Pr0.5Sr0.5MnO3: A photoemission study

The valence band electronic structure of Pr

Mn-induced modifications of Ga 3d photoemission from (Ga, Mn) As: evidence for long range effects

_{0.5}

Pseudogap behavior in Pr

Sr

_{0.5}

_{0.5}

Sr

MnO

_{0.5}

_3

MnO

has been investigated across its paramagnetic metallic (PMM) - ferromagnetic metallic (FMM) - antiferromagnetic insulator (AFMI) transition. Using surface sensitive high resolution photoemission we have conclusively demonstrated the presence of a pseudogap of magnitude 80 meV in the near Fermi level electronic spectrum in the PMM and FMM phases and finite intensity at the Fermi level in the charge ordering (CO)-AFMI phase. The pseudogap behavior is explained in terms of the strong electron-phonon interaction and the formation of Jahn Teller (JT) polarons, indicating the charge localizations. The finite intensity at the Fermi level in the insulating phase showed a lack of charge ordering in the surface of the Pr

_3

_{0.5}

: A photoemission study

Sr