Magnetic properties of RCo2 compounds in the exchange-striction model of ferrimagnets

The original version of the exchange-striction model of a ferrimagnet has been employed for calculating a number of magnetic properties of RCo2 ferrimagnets, where R = Er, Ho, Dy, Tb, and Gd are rareearth ions. The following magnetic properties are calculated: pressure dependence of the Curie temperature (D cent (D)), temperature dependences of magnetization in sublattices of cobalt and rare-earth atoms, and isotherms of magnetization of these lattices at D cent > D cent (D). For an ErDD 3/4 (2) sample, the De-D cent phase diagram has been constructed and the magnetization in the magnetic fields De = 0-70 D cent has been calculated. The calculated and experimental results have been compared. Based on the exchange-striction model, the qualitative explanation of the difference in the type of the magnetic phase transformation in the intermetallic compounds with R = Tb and Gd and R = Er, Ho, and Dy is given.