The magnetic phase transitions in R(Co, Al)2 compounds (R: Dy, Ho, Er)

✍ Scribed by N.H. Duc; T.D. Hien; R.Z. Levitin; A.S. Markosyan; P.E. Brommer; J.J.M. Franse

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 356 KB
• Volume: 176
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(92)90011-g

✦ Synopsis

The type of the magnetic phase transition in the R(Co~ xAl~) 2 (R = Dy, Ho, Er) compounds is studied by means of magnetization, thermal-expansion and electrical-resistivity measurements. With increasing AI content, a change from a first-order to a second-order transition is observed, at x = 0.075, 0.075 and 0.025 for Er, Ho and Dy, respectively. An explanation is offered in terms of the Inoue-Shimizu model by introducing a concentration dependence of T3, the temperature at which a3(T) changes sign (a 3 is the coefficient of the M4a-term in the expansion of the free energy of the d-subsystem). In fact, T a is taken proportional to T,,, the temperature at which the susceptibility of the corresponding Y(Co, AI)2 shows a maximum.