Magneto caloric effect in (DyxGd1-x)(3)Ga5O12 for adiabatic demagnetization refrigeration.

摘要

Gadolinium and dysprosium gallium garnet single crystals (DyxGd1-x)(3)Ga5O12 (x = 0, 0.5 and 1) have been investigated for adiabatic demagnetization refrigeration used as magnetic materials between 0.5 and 5 K. Specific heat measurement of (Dy0.5Gd0.5)(3)Ga5O12 showed a large and broad peak similar to that of Gd3Ga5O12 and it suggests that the geometrical frustration in Gd3Ga5O12 Still remains in (Dy0.5Gd0.5)(3)Ga5O12. Magneto caloric effect of (Dy0.5Gd0.5)(3)Ga5O12 was about four times larger than that of Gd3Ga5O12 for the magnetic field of I T between 0.5 and 5 K. Therefore, the magnetic entropy change of Gd3Ga5O12 by the external magnetic fields could be enhanced by substituting Dy3+ ion for Gd3+ ion for the magnetic fields of < 2 T between 0.5 and 5 K. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 6]