Magnetocaloric properties of HoFeO3 single crystal are investigated along the direction [100]. Magnetic field dependent magnetization isotherms at different temperatures undergo a metamagnetic transition, entropy change as large as 19.2 J/kg K and 15.8 J/kg K are obtained at 7 T in the vicinity of antiferromagnetic ordering temperature of Ho3+ and the metamagnetic transition, respectively. The coupling of Ho and Fe spins generates the compensation behavior at 6.5 K, separating the two large magnetic entropy change. Its refrigeration capacity (RC) value, as high as 220 J/kg, is appreciable and can be considered as a promising magnetic refrigerant. New evidence for spin reorientation of Fe3+ in HoFeO3 is also provided by the change of magnetic entropy.Highlights► We calculate the magnetic entropy of HoFeO3 single crystal firstly. ► We find the exotic magnetic entropy phenomenon and give the reasonable explain. ► The new spin reorientation evidence is supported. ► The large RC value indicates the material to be potential magnetic refrigerant.

The lattice effect and magnetic transition behaviors of (Pr1−yNdy)0.67Sr0.33MnO3 (y=0, 1/4, 2/4, 3/4, 1) samples under superposed magnetic fields (i.e. the superposed AC and DC magnetic field) were systematically studied in the temperature range from 4.2 to 330 K. The results show that the magnetic transition temperature (Curie temperature, TC) of (Pr1−yNdy)0.67Sr0.33MnO3 shifts to a lower temperature as Nd substitutes for Pr, which is related to the degree of lattice distortion. The magnetization of samples increases with the increase in applied magnetic field and the in-phase-part of the AC susceptibility decreases as the superposed DC magnetic field increases. Under superposed magnetic fields, a characteristic sharp peak of the in-phase part of the susceptibility appears near TC. For the (Pr1−yNdy)2/3Sr1/3MnO3 system, as the Nd content increases, the peak temperature of the relative variation for the in-phase part of magnetic susceptibility (Eχ′=Δχ′/χ′dc) decreases, in consistent with that of the magnetoresistivity of this system. The magnetic transition behaviors under superposed magnetic fields for the manganite systems are discussed.

Highly oriented Fe1.03Te0.55Se0.45 crystal with Tc∼14.4K was grown through Optical Zone-Melting Technique. Resistivity versus temperature under various magnetic fields was measured. The upper critical field μ0Hc2 estimated from the WHH equation reaches 42.6 T, which is in good agreement with experimental results. The Ginzburg–Landau (GL) coherence length at zero temperature was estimated to be 27.77–29.33 Å. The activation energy determined from the Arrhenius dependence of the resistivity reaches ∼103 K. Due to its relatively low Tc compared with FeAs superconductors and high-Tc cuprates, we suggest that the high activation energy should be attributed to the existence of excess Fe located in FeTe(Se) layers, which might induce vacancies into the system. The e–ph coupling parameter is estimated to be 1.40, revealing that Fe1.03Te0.55Se0.45 belongs to the strong electron–phonon coupling system.

Magnetocaloric properties of HoFeO3 single crystal are investigated along the direction [100]. Magnetic field dependent magnetization isotherms at different temperatures undergo a metamagnetic transition, entropy change as large as 19.2 J/kg K and 15.8 J/kg K are obtained at 7 T in the vicinity of antiferromagnetic ordering temperature of Ho3+ and the metamagnetic transition, respectively. The coupling of Ho and Fe spins generates the compensation behavior at 6.5 K, separating the two large magnetic entropy change. Its refrigeration capacity (RC) value, as high as 220 J/kg, is appreciable and can be considered as a promising magnetic refrigerant. New evidence for spin reorientation of Fe3+ in HoFeO3 is also provided by the change of magnetic entropy.Highlights► We calculate the magnetic entropy of HoFeO3 single crystal firstly. ► We find the exotic magnetic entropy phenomenon and give the reasonable explain. ► The new spin reorientation evidence is supported. ► The large RC value indicates the material to be potential magnetic refrigerant.