Size-induced transition from magnetic ordering to kondo behavior in (Ce,Al) compounds
Magnetic ordering and Kondo behavior coexist in three (Ce,Al)-based compounds: CeAl2, Ce3Al, and Ce3Al11. A common feature apparently independent of crystal structures also prevails in terms of the size-induced transition between these two magnetic phenomena. As the particle size is reduced to nanoscale, the specific heat anomaly associated with the magnetic ordering diminishes. Although the Kondo temperature also decreases, the entropy associated with Kondo anomaly exhibits a large increase. This results in an enhancement of the Kondo behavior and an increased coefficient gamma of the linear term in specific heat. For example, in 80 A CeAl2 the extrapolated r(0) reaches 9000 mJ mol Ce-1 K-2.
Chen
YY
Institute of Physics, Academia Sinica, Taipei, Taiwan, Republic of China.
Yao
YD
Wang
CR
Li
WH
Chang
CL
Lee
TK
Hong
TM
Ho
JC
Pan
SF