Thermodynamic Fluctuations in Magnetic Phase Transition: Invar as a Prototype

2009/03/27 by Y. Wang, S.L. Shang, S. L. Shang +5 · 4 citations
Materials Science · Physics and Astronomy · #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #Thermal Expansion and Ionic Conductivity #cond-mat.mtrl-sci #cond-mat.stat-mech

paper · pdf · doi:10.1080/09500839.2010.508446

published as Philosophical Magazine Letters Volume: 90 Issue: 12 Pages: 851-859 Published: 2010 · Rephased title and abstract; Reploted figures; Reordered references

arxiv created 2009/03/27 · openalex publication_date 2010/07/31 · arxiv updated 2014/02/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29

Abstract

We propose a first-principles formulism for system with spin fluctuations and apply it to the ordered Fe3Pt to uncover the Invar anomalies, including negative thermal expansion and spontaneous magnetization. The theory has coherently predicted the finite temperature intermixing between the fully ferromagnetic configuration and the spin-flipping configurations. We also discover a tri-critical point at which a high-temperature second-order phase transition, between the fully ferromagnetic configuration and the spin-flipping configurations, becomes first-order at low temperatures.

Citations

• Projector augmented-wave method
• From ultrasoft pseudopotentials to the projector augmented-wave method
• Generalized Gradient Approximation Made Simple
• Mean‐field potential approach to the quasiharmonic theory of solids

Cited by

• An efficient ab-initio quasiharmonic approach for the thermodynamics of solids
• Thermal Expansion Anomaly Regulated by Entropy
• Density Functional Theory ToolKit (DFTTK) to Automate First-Principles Thermodynamics via the Quasiharmonic Approximation
• Invar [wikipedia]

Related

• A common magnetic origin for the Invar effects in fcc iron-based ferromagnets
• The re-examined phenomenological phase transitions theory for ferromagnets
• Critical exponents and scaling invariance in the absence of a critical point
• Kinetic arrest, and ubiquity of interrupted 1st order magnetic transitions
• Hybrid ab initio method for examining thermal properties in magnetic materials