Chen YY, Yao YD, Wang CR, Li WH, Chang CL, Lee TK, Hong TM, Ho JC, Pan SF
Institute of Physics, Academia Sinica, Taipei, Taiwan, Republic of China.
Phys Rev Lett. 2000 May 22;84(21):4990-3. doi: 10.1103/PhysRevLett.84.4990.
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.
磁有序和近藤行为共存于三种基于（铈，铝）的化合物中：CeAl2、Ce3Al和Ce3Al11。在这两种磁现象之间由尺寸诱导的转变方面，一个显然与晶体结构无关的共同特征也很普遍。随着粒径减小到纳米尺度，与磁有序相关的比热异常减小。尽管近藤温度也降低，但与近藤异常相关的熵却大幅增加。这导致近藤行为增强，比热线性项的系数γ增大。例如，在80埃的CeAl2中，外推的γ(0)达到9000毫焦·摩尔Ce-1·K-2。
