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In this article, we report research data for the isothermal magnetization of a composite consisting of Cd3As2 Dirac semimetal and MnAs ferromagnet (30 mol %) at pressures up to 5 GPa. A magnetic transformation in MnAs inclusions, the size of which presumably varies from a micro- to nanoscale, has been found to be similar to that in bulk MnAs compound, except for a hysteresis in the range of magnetostructural transformation. Under hydrostatic pressure, a magnetization maximum has been revealed at pressures P ≥ 0.77 GPa, which is indicative of ferromagnetic ordering improvement. The conclusion has been drawn that that the above features are due to the superparamagnetic nature of nanometer-sized MnAs inclusions in the Cd3As2 matrix. [ABSTRACT FROM AUTHOR]

The specific heat of PrSrMnFeO ( x = 0 and 0.1) manganites was measured in the temperature range 80-350 K. A nature of the ferromagnetic phase transition is studied via the analysis of a specific heat critical behavior near the Curie temperature with account of correction to the scaling. The critical indices calculated with the account of correction to the scaling α = −0.0981 and −0.1208 for x = 0 and 0.10, correspondingly, are close to those of the 3D Heisenberg model. [ABSTRACT FROM AUTHOR]

An investigation of the critical behavior of the specific heat of the manganites La1-xAgxMnO3 ×(x=0.1,0.15,0.2) near the Curie temperature is carried out. The behavior of the universal critical parameters near the phase transition point is established. All of the samples studied correspond to the ferromagnetic Heisenberg 3D universality class of critical behavior, with the critical exponent α=-0.115, -0.106, and -0.106 for La0.9Ag0.1MnO3, La0.85Ag0.15MnO3, and La0.8Ag0.2MnO3, respectively. It is shown that the universality class of the critical behavior of the specific heat of the manganites La1-xAgxMnO3 is independent of the silver concentration. [ABSTRACT FROM AUTHOR]