Author(s):
Sousa, Pedro M. ; Dias, Sonia A. ; Conde, Olinda ; Silvestre, António Jorge ; Branford, William R. ; Morris, Benjamin ; Yates, Karen ; Cohen, Lesley F.
Date: 2007
Persistent ID: http://hdl.handle.net/10400.21/1759
Origin: Repositório Científico do Instituto Politécnico de Lisboa
Subject(s): CrO2; Ferromagnetism; Spin Polarization; Transport Properties; XRD; Chemical-Vapor-Deposition; Half-Metallic Ferromagnet; Pulsed-Laser Deposition; Oxide Thin-Films; Chromium-Oxide; Epitaxial-Growth; Magnetic-Properties; Spin Polarization; Point-Contact; Magnetoresistance
Description
In this work we report on the structure and magnetic and electrical transport properties of CrO2 films deposited onto (0001) sapphire by atmospheric pressure (AP)CVD from a CrO3 precursor. Films are grown within a broad range of deposition temperatures, from 320 to 410 degrees C, and oxygen carrier gas flow rates of 50-500 seem, showing that it is viable to grow highly oriented a-axis CrO2 films at temperatures as low as 330 degrees C i.e., 60-70 degrees C lower than is reported in published data for the same chemical system. Depending on the experimental conditions, growth kinetic regimes dominated either by surface reaction or by mass-transport mechanisms are identified. The growth of a Cr2O3 interfacial layer as an intrinsic feature of the deposition process is studied and discussed. Films synthesized at 330 degrees C keep the same high quality magnetic and transport properties as those deposited at higher temperatures.
