A research group in USTC investigate the anisotropic properties in a manganite film and fund that on LSAT (001) substrate, the La0.325Pr0.3Ca0.375MnO3 film shows a large resistivity anisotropy as high as 105%. The resistivity measured along [01-1] direction is much lower than that along [100] direction.
This research was done by using the STM/MFM/AFM (SMA) system in High Magnetic Field Laboratory,CAS
This work used the SMA system in SHMFF.Magnetic force microscopy was used to observe the evolution of the phase transitions in magnetic fields. The MFM images are shown below. As the field was increased, dark regions corresponding to ferromagnetic (FM) domains gradually nucleate and grow in the matrix of the antiferromagnetic phase. The surprise is that the ferromagnetic domains form a regular pattern with straight and parallel FM domains along [01-1] direction, consistent with the lower resistivity. The direct imaging on the microscopic scale provides further insights to the macroscopic properties.
The SMA system is one of the measurement facilities in SHMFF. It’s a home-built system that consists of a scanning tunneling microscope, a magnetic force microscope and an atomic force microscope. It is developed by the group of Prof. Qingyou Lu. It can be
inserted into a 20 T superconducting magnet, thus it’s a powerful tool to explore the properties materials on the microscale.
This work was recently published in Appl. Phys. Lett. 104, 203501 (2014).The link to the paper: http://scitation.aip.org/content/aip/journal/apl/104/20/10.1063/1.4878557.
