Magnetic field induced low temperature upturn of magnetization in highly Ca-doped La0.1875Ca0.8125MnO3 polycrystalline compound

In our present study we have reported the magnetic properties of highly Ca-doped polycrystalline compound La0.1875Ca0.8125MnO3. Along with the conventional charge ordered antiferromagnetic ground state, a small ferromagnetic phase fraction is present at the low temperature. The effect of the external magnetic field markedly modifies the ground state of the compound. Our experimental results indicate that in addition to the ferromagnetic phase fraction, another field induced super paramagnetic phase grow at low temperature (T < 50 K) above H = 10 kOe magnetic field within the charge ordered antiferromagnetic matrix. The nature of the temperature dependent magnetization curves influenced by the external applied magnetic field was observed and analyzed using Langevin theory of super paramagnetism.