Author(s): Charles Bryant, James Payne, Calleigh Brannan, Rodolfo Marquez Tavera, Maitri P. Warusawithana, Tom M. Pekarek
We have studied how the ferromagnetic transition and other magnetic properties vary with concentration. Data collected has been analyzed, using SigmaPlot software, to better evaluate reduced dimensionality effects on the magnetic behavior of lanthanum strontium manganite (La1-xSrxMnO3 or LSMO). Measurements using reflection high-energy electron diffraction (RHEED) were incorporated to verify that the crystals are high quality. We then measured the magnetic properties using our Superconducting Quantum Interference Device (SQUID) magnetometer. These magnetic properties have been analyzed to determine the characteristics of the superlattice. The primary goal has involved the magnetic data collection and analysis. Our analysis has investigated the major ferromagnetic properties and other qualities of the samples. Critical temperature, saturated magnetic moment, remnant moment, and Bohr magneton versus temperature as well as the ferromagnetic to paramagnetic transition temperature have been studied in detail over a sample range of Sr concentration values from x = 0.04 to 0.20. This has provided a better insight into the interesting behavior exhibited at concentration x = 0.04, where the canted anti-ferromagnetic properties begin to become apparent in this doping range but aren’t apparent at higher doping (higher concentrations). Thanks to the research grant provided by The Office of Undergraduate Research we have the helium gas that is essential for producing the liquid helium needed for more measurements that will be required to fine tune and verify our data for scientific publication.
