On the classical critical behavior of the specific heat capacity of a model of structural phase transitions with a long-range interaction

• Published in: Journal of physics. Conference series Vol. 2436; no. 1; pp. 12012 - 12016
• Main Author: Pisanova, E S
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.01.2023
• Subjects: Anharmonicity; Critical point; Heat; Phase transitions; Physics; Specific heat
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2436/1/012012

Abstract The critical specific heat capacity c of a d -dimensional model describing structural phase transitions in an anharmonic crystal with a long-range interaction (decreasing at large distances r as r − d − σ , 0 < σ ≤ 2) is studied near the classical critical point T c . At temperatures T > T c and for dimensions σ < d < 2 σ ( σ and 2 σ are the lower and the upper critical dimensions, respectively) the critical specific heat capacity is obtained in the form c ≈ 1 − Dε α s , where D > 0 and α s < 0 depend only on the ratio d/σ , and ε = T/T c −1 is a measure of the deviation from the critical point. For three fixed values of the ratio d/σ the dependence c ≈ c ( ε ) is graphically presented. It is shown that at all temperatures T ≤ T c the specific heat capacity retains its maximum value, c max = 1. The critical exponent α s , obtained here, coincides with that of the known mean spherical model, while c max is different for the two models.