Abstract
This article comprises of the structural, magnetic, magneto-caloric and critical behavior study of single phase perovskite manganite LaMnO3+delta sample synthesized by traditional Solid State route. X-ray powder diffraction (XRD) at room temperature indicates the single phase trigonal crystalline structure of LaMnO3+delta with hexagonal setting R (3) over barc. Magnetic, magnetocaloric and critical behavior are studied using temperature dependent magnetization (M-T) and applied magnetic field dependent magnetization (M-H) data probed by Physical Property Measurement System (PPMS). The second order ferromagnetic to paramagnetic (FM-PM) phase transition is observe at Curie temperature (T-C similar to 180 K). This phase transition is responsible for maximum entropy change (Delta S-M(max)) of 0.451(1) J/kg K at applied magnetic field of 6 Tesla with relative cooling power (RCP) of 54.293(5) J/ kg. At T-C, the order of magnetic phase transition is examined by employing Modified Arrott plots (MAP), Kouvel Fisher (KF) and simple isotherm analysis technique. The obtained values of critical exponent's beta approximate to 0.365 +/- 0.06, gamma approximate to 1.14 +/- 0.04 and delta approximate to 4.16 +/- 0.10 elaborate that the magnetic phase transition coordinated well with the 3D-Heisenberg model at T-C approximate to 180 K and are confirmed by scaling equations of state. Similarly the change in magnetic entropy (.SM) versus applied magnetic field recorded complies with the power law Delta S = (H)(n) with n = 0.64 at T-C= 180 K.