Griffiths phase and spontaneous magnetization in polycrystalline Co50V34Ga16 alloy

Evolution of ferromagnetic cluster in perovskite La0.88Sr0.12MnO3 nanocrystalline detected by EPR spectrum

“…1 c. Figure 1 d shows the magnified magnetic hysteresis loop of T = 350 K. Obviously, the loop shows a perceivable inflection, indicating the existence of FM behavior. At T = 300 K, between 280 K and 316 K, its magnetic hysteresis loop shows obvious FM behaviors, which means that the localized FM clusters have been formed 6 . At T = 50 K and T = 175 K, lower than the Curie temperature, its magnetic hysteresis loop implies a pure FM state.…”

“…Griffiths singularities have been reported in many complex magnetic materials including perovskite manganites R 1 −x A x MnO 3 (where R is a rare-earth element such as La, Pr, Sm and A are divalent alkaline-earth element Ca, Sr and Ba) 1 – 5 , rare-earth intermetallic system and Heusler alloy 6 – 9 . Generally, the Griffiths singularity accounts for a magnetic system with a random distribution of magnetic interactions given by disordered sets in such a lattice or valence/spin state.…”

“…We proposed that the appearance of the Griffiths phase was due to the short FM correlation in the PM regime enhanced by surface spin ordering. Keywords La 0.88 Sr 0.12 MnO 3 nanocrystalline, Griffiths phase, EPR spectrum, Ferromagnetic clusters Griffiths singularities have been reported in many complex magnetic materials including perovskite manganites R 1−x A x MnO 3 (where R is a rare-earth element such as La, Pr, Sm and A are divalent alkaline-earth element Ca, Sr and Ba) 1-5 , rare-earth intermetallic system and Heusler alloy [6][7][8][9] . Generally, the Griffiths singularity accounts for a magnetic system with a random distribution of magnetic interactions given by disordered sets in such a lattice or valence/spin state.…”