Abstract
The distribution of magnetic domain pinning fields was determined in ferromagnetic GaMnAs films using the angular dependence of the planar Hall effect. A major difference is found between the pinning field distribution in as-grown and in annealed films: the former showing a strikingly narrower distribution than the latter. This effect, which we ascribe to differences in the degree of uniformity of magnetic anisotropy, provides a better understanding of magnetic domain landscape in GaMnAs, a subject of current intense interest.
Highlights
Many of its physical properties, such as the effect of low temperature annealing on the Curie temperature [4,5,6,7,8], the role of Mn ions at interstitial positions [7, 9, 10], and the dependence of magnetic anisotropy on strain and on carrier density, have been extensively investigated [11,12,13]
Wang et al [15], on the other hand, who carried out ac susceptibility studies on GaMnAs films, interpret their data in terms of temperature-dependent changes in magnetic anisotropy by assuming a single uniform magnetic phase
This study demonstrated a landscape comprised of multiple domains with different directions of magnetization coexisting during magnetization reversal
Summary
There is a major difference between the pinning field distribution in as-grown and in annealed films, the former showing a strikingly narrower distribution than the latter This conspicuous difference can be attributed to the degree of non-uniformity of magnetic anisotropy in both types of films. The PHR is seen to vary between positive and negative values as the field is rotated, showing a hysteresis between clockwise (CW) and counterclockwise (CCW) rotations This type of angular dependence of PHR has already been observed in GaMnAs films [19, 20], and can be described by the following expression [21]. This region includes the crossing by the field direction of the [110] crystallographic axis. The fractional area p of magnetization along the [010] direction at any point during the transition from [100] to [010] (i.e., in the case of CCW rotation of the field) can be calculated from the simple relation, p
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
