To study magnetic refrigerants useful at low temperatures below 20K, new pseudo-binary garnet single crystals of Gd
3(Ga
1-xAl
x)
5O
12 with
x=0.1, 0.2, 0.3 and 0.4, having about 25mm in diameter and 50mm in length, have been grown using the Czochralski technique. The effective magnetic moments
p of the crystals are about 7.9μ
B, independent of
x, and the paramagnetic Curie temperatures θ
p are-0.60 to -1.11K, showing the minimum at
x=0.2. Based on magnetic measurements and adiabatic demagnetization experiments in magnetic fields up to 75 and 60kOe, respectively, the magnetic entropy change
ΔSM and the entropy
S are estimated to be almost the same for all the crystals.
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