Heat capacity studies on RAuAl compounds (R  La, Ce and Nd)

✍ Scribed by Latika Menon; S.K Dhar; S.K Malik

• Book ID: 103941553
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 207 KB
• Volume: 223-224
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(96)00100-7

✦ Synopsis

In the RAuA1 series, the compound CeAuA1 shows Kondo lattice behaviour and orders antiferromagnetically with a N6el temperature of ~ 3.8 K. The non-magnetic member, LaAuA1, is metallic and non-superconducting down to 2 K, while NdAuA1, has a ferromagnetic ground state with a Curie temperature of ~ 10 K. Heat capacity measurements have been carried out on these compounds in the temperature range 2-20 K. The electronic specific heat coefficient, 7, of LaAuAI is ~ 1 m J/mol K 2, typical of normal metallic systems. The heat capacity of CeAuA1 shows a rise at about 4 K due to the magnetic ordering. The 7 value for CeAuA1, in the temperature range 8-15 K, is ~ 100 mJ/mol K 2, and the entropy change due to magnetic transition is about 4 J/mol K which is appreciably reduced compared to the value R In(2) expected for a crystal-field-split doublet ground state. In the case of NdAuA1, a rise in the heat capacity is observed at about 10 K due to the ferromagnetic ordering while the entropy change due to the transition is about 5.3 J/ mol K-close to the value of R ln(2).