Magnetic Properties Of Metastable Gdcr Alloys

We report on the magnetization, magnetocaloric effect, magnetic ordering temperatures, saturation magnetic moments and anisotropy of sputter-deposited GdxCr1-x alloys with Gd atomic concentrations, x, ranging from 0.13 to 0.52. The complex magnetic nature of the GdCr films was revealed from the M×H isotherms, which do not show saturation even at an applied field of 70 kOe and a temperature of 2 K and do not exhibit a linear behavior at higher temperatures. For some of the samples, the isotherms were used to determine the isothermal entropy variation as a function of temperature, for a change of 50 kOe in the applied magnetic field. The saturation magnetic moment varies with x and follows the dilution law, implying that the Cr atoms do not contribute to the total moment of the GdCr alloys. Both static magnetization and dynamic susceptibility measurements reveal the existence of a magnetic glassy behavior in the alloys, which occurs below a freezing temperature. 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