Emergence of Griffiths phase and exploiting magnetic ordering state in the intermetallic LaCeCo7.

We have studied the evolution of Griffiths phase and the magnetic ordering state in the intermetallic compound LaCeCo 7. A ferromagnetic-like ordering phase is built up at 260 K but an anomalous magnetic susceptibility related to the Griffiths phase occurs in 300 K. The studies of critical behavior confirm that LaCeCo 7 exhibits a second-order paramagnetic-ferromagnetic phase transitions. The critical exponents of β = 0.665, γ = 1.151, and δ = 2.728 determined by the magnetic field dependence on magnetic entropy change method deviate a little from the theoretical estimated long-range mean-field model (β = 0.5, γ = 1.0, and δ = 3.0). This result implies that the disorder effect in the intermetallic LaCeCo 7 possibly plays a key role on the anomalous critical behavior and the establishment of magnetic ordering phase. [ABSTRACT FROM AUTHOR]