We report the observation of weak ferromagnetism up to T(C) approximately 250 K and a spin-glass-like behavior at temperatures below T(SG) approximately 30 K in nanoscale MnO particles. T(SG) is considerably lower and T(C) is much higher than the Néel temperature (T(N)=122 K) of bulk MnO. While the dominant low temperature behavior (below 30 K) may be attributed to the effects studied in this s...

Low-temperature thermodynamic properties of strongly interacting Fermi liquids with a fermion condensate are investigated. We demonstrate that the spin susceptibility of these systems exhibits the Curie-Weiss law, and the entropy contains a temperature-independent term. The excessive entropy is released at the superconducting transition, enhancing the specific heat jump deltaC and rendering it ...

We estimate, using high-temperature series expansions, the transition temperatures of the spin 1 2 , 1 and 3 2 Heisenberg ferromagnet and antiferromagnet in 3dimensions. The manner in which the difference between Curie and Néel temperatures vanishes with increasing spin quantum number is investigated. Curie and Néel Temperatures of Quantum Magnets 2 It is well known that in classical spin model...

We demonstrate the importance of thermal effects such as temperature-induced electronic, magnetic and vibrational excitations, as well as structural defects in the first-principles calculations of the magnetic critical temperature of complex alloys using half-Heusler Ni 1−x Cu x MnSb alloys as a case study. The thermal lattice expansion and one-electron excitations have been accounted for self-...

Hardening of steel wires requires heating the wires above their Curie temperature, temperature at which the material becomes nonmagnetic causing a sudden change in the load. This change affects to the induction heating converters and is difficult to be evaluated due to the complexity of the problem and the interdependence of the parameters. In this paper a continuous Post-Curie wire heating mod...

Using the Kondo lattice model with classical spins in infinite dimension, magnetic phase transition in the perovskite-type 3d transition-metal oxide La1−xSrxMnO3 is theoretically studied. On the Bethe lattice, the self-consistency equations are solved exactly. Curie temperatures at the region of double-exchange ferromagnetism 0.1 <∼ x <∼ 0.25 as well as the Nèel temperature at x = 0 are well re...

The polycrystalline manganite La0.75Sr0.25MnO3 prepared by an alternative carbonate precipitation route reveals the rhombohedral perovskite structure. Magnetization isotherms measured up to 2 T are used to determine Curie temperature of 332 K by means of Arrott plot. Maximum of magnetic entropy change is found at Curie temperature. The relative cooling power equal to 64 J/kg for 1.5 T magnetic ...