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Updated: Apr 5, 2026
09:45
Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition
Published on: July 26, 2016
12.9K
Nonlocal quartic interactions and universality classes in perovskite manganites
Rohit Singh1, Kishore Dutta2, Malay K Nandy1
1Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781 039, India.
Summary
This study explores critical behavior in perovskite manganites using a modified Ginzburg-Landau model. The findings suggest nonlocal interactions capture diverse magnetic phase transition universality classes.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Statistical Mechanics
Background:
- Perovskite manganites exhibit complex magnetic phase transitions.
- Understanding critical behavior is key to their technological applications.
- Ginzburg-Landau models are crucial for describing phase transitions.
Purpose of the Study:
- To investigate the paramagnetic-to-ferromagnetic phase transition in perovskite manganites.
- To analyze critical behavior using a modified Ginzburg-Landau model with screened nonlocal interactions.
- To determine critical exponents and compare them with experimental data.
Main Methods:
- Application of Wilson's renormalization-group scheme at one-loop order.
- Utilizing an epsilon expansion (ε=d(c)-d) for analytical calculations.
- Modification of the Ginzburg-Landau model with a screened nonlocal interaction in the quartic term.
Main Results:
- The Fisher exponent η was found to be O(ε).
- The correlation exponent ν was determined to be 1/2+O(ε).
- Calculated critical exponents in three dimensions align well with experimental estimates for various perovskite manganites.
Conclusions:
- The nonlocal model Hamiltonian effectively describes a broad range of universality classes for phase transitions.
- The theoretical framework provides a good match for experimental observations in perovskite manganites.
- This work advances the understanding of critical phenomena in magnetic materials.
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