The hexagonal layered compound, EuPtP, exhibits two valence transitions, at T1 = 235K and T2 = 190K, and an antiferromagnetic order at TN = 8.6K. We have examined the effects of magnetic field and pressure, and the specific heat. Analysis of the high-field experiments confirms that half of Eu are in a divalent state at the lowest temperature, and that the number of Eu2 + increases discontinuously at T2 and T1 with increasing temperature. The magnetic entropy reaches ∼ 22JK- 1mol- 1 at room temperature, which is larger than that expected for J = 7/2 of Eu2 + (17.3 JK- 1mol - 1). This is in good agreement with the magnetic entropy deduced from the interconfigurational fluctuation model, which explains the valence transition in Eu(Pd1 - xPtx)2Si2. The application of pressure shifts T1 and T2 higher and suppresses the intermediate phase (β phase, T2 < T < T1), whereas it does not change the properties of the low-temperature phase (γ phase, T < T2) and the TN.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics