Tuning sign reversed oscillatory magneto-resistance via controlling hole concentration in La0.3Pr0.4Ca0.3MnO3∕LaAlO3 thin films

The temperature and magnetic field dependent oscillatory magneto-resistance of a compressively strained La0.3Pr0.4Ca0.3MnO3 thin film was measured for various post annealing conditions (i.e., Argon/Air) in order to study the effects of hole concentration on the magnitude of the negative AMR below the crossover temperature T*. It was found that Ar and Air annealing have adverse effects on the negative AMR below T*. Interestingly, annealing driven hole doping and A-site Pr doping show similar effects on the negative AMR of these films. The mechanism responsible for these changes is discussed.