  Stable Tsai-type quinary 1/1 and 2/1 approximant crystals (ACs) with chemical
compositions Au56.25Al10Cu7In13Tb13.75 and Au55.5Al10Cu7In13Tb14.5,
respectively, exhibiting ferromagnetic (FM) long-range orders were successfully
synthesized and studied for their magnetic properties and magnetocaloric
effect. The 1/1 and 2/1 ACs primarily differ in their long-range atomic
arrangement and rare earth (RE) distribution, with the latter approaching
quasiperiodic order while still preserving periodicity. Analyses based on the
scaling principle and Kouvel-Fisher (KF) relations suggested mean-field-like
behavior near Curie temperatures in both compounds. From magnetization
measurements and the Maxwell equation, a magnetic entropy change of -4.3 and
-4.1 J/K mol Tb were derived under a magnetic field change of 7 T for the 1/1
and 2/1 ACs, respectively. The results indicated a prominent role of
intra-cluster magnetic interactions on critical behavior and magnetic entropy
of the Tsai-type compounds.
