%0 Journal Article
%A Maryško, M.
%A Hejtmánek, J.
%A Laguta, V.
%A Sofer, Z.
%A Sedmidubský, D.
%A Šimek, P.
%A Veselý, M.
%A Mikulics, M.
%A Buchal, C.
%A Macková, A.
%A Malínský, P.
%A Wilhelm, R. A.
%T Ferromagnetic and paramagnetic magnetization of implanted GaN:Ho,Tb,Sm,Tm films
%J Journal of applied physics
%V 117
%N 17
%@ 1089-7550
%C Melville, NY
%I American Inst. of Physics
%M FZJ-2015-02738
%P 17B907 
%D 2015
%X The SQUID magnetic measurements were performed on the GaN films prepared by metal-organic vapour phase epitaxy and implanted by Tb3+, Tm3+, Sm3+, and Ho3+ ions. The sapphire substrate was checked by the electron paramagnetic resonance method which showed a content of Cr3+ and Fe3+ impurities. The samples 5 × 5 mm2 were positioned in the classical straws and within an estimated accuracy of 10−6 emu, no ferromagnetic moment was detected in the temperature region of 2–300 K. The paramagnetic magnetization was studied for parallel and perpendicular orientation. In the case of GaN:Tb sample, at T = 2 K, a pronounced anisotropy with the easy axis perpendicular to the film was observed which can be explained by the lowest quasi-doublet state of the non-Kramers Tb3+ ion. The Weiss temperature deduced from the susceptibility data using the Curie-Weiss (C-W) law was found to depend substantially on the magnetic field.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000354984100230
%R 10.1063/1.4916761
%U https://juser.fz-juelich.de/record/189601