TITLE:
Characteristics of La0.7Sr0.3MnO3 Films Modified by Aluminum Ions Implantation and Post-Implantation Annealing
AUTHORS:
Shaoqun Jiang, Gang Wang, Xinxin Ma, Xinxin Ma, Guangze Tang
KEYWORDS:
La0.7Sr0.3MnO3 Film, Plasma Based Ion Implantation, Annealing; Metal-Insulator Transition, Emittance
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.1,
January
20,
2015
ABSTRACT: The magnetron sputtered La0.7Sr0.3MnO3 films were implanted with different doses (5 ′ 1015 ions×cm?2 and
5 ′ 1016 ions×cm-2) of
Al ions at different negative pulsed voltages (30 kV and 50 kV) by plasma based
ion implantation and then annealed at 973 K for 1 h in air. The microstructure,
surface morphologies, surface roughness, metal-insulator transition and room
temperature emittance properties of the post-implantation annealed films were
investigated and compared with those of the La0.7Sr0.3MnO3 film annealed at 973
K for 1 h in air. The results indicate that the post- implantation annealed
films show single perovskite phase and obvious (100) preferred orientation
growth. The Mn-O bond length, surface roughness and metal-insulator transition
temperature (TMI) of the films can be effectively adjusted by changing
implantation voltage or implantation dose of Al ions. However, the change of
implantation parameters just has a small effect on room temperature emittance
of the films. Compared with the annealed film, the post-implantation annealed
films have shorter Mn-O bond length and lower room temperature emittance. The TMI
of the films implanted at low voltage is lower than that of the annealed film,
which mainly results from the degradation of oxidization during annealing
process and the part displacement of Mn3+-O2+- Mn4+ double exchange channels by
Al3+-O2?-Mn4+. The post-implanted annealed film implanted at 50 kV/5 ′ 1016 ions×cm-2 has
a higher TMI than the annealed film, which is 247 K. The increase of TMI of the
film implanted with high dose of Al ions at high voltage can be attributed to
the improvement of microstructure.