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Anomalous Schottky specific heat and structural distortion in ferromagnetic PrAl2
Arjun K Pathak1, D Paudyal, Y Mudryk
1The Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011-3020, USA. pathak138@ameslab.gov
Physical Review Letters
|May 21, 2013
Summary
Praseodymium dialuminide (PrAl2) exhibits a unique structural change at low temperatures, transitioning from cubic to tetragonal symmetry. This transformation, influenced by magnetic fields and crystal field splitting, explains its unusual thermal properties.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Rare Earth Compounds
Background:
- Praseodymium dialuminide (PrAl2) is a rare earth intermetallic compound.
- Unusual low-temperature phenomena have been observed in PrAl2, distinguishing it from other rare earth dialuminides.
Purpose of the Study:
- To investigate the structural phase transition in PrAl2 at low temperatures.
- To understand the relationship between magnetic fields, crystal field splitting, and the observed thermal properties.
Main Methods:
- Experimental observation of structural distortion and magnetic field effects.
- First principles calculations to analyze electronic structure and crystal field splitting.
Main Results:
- PrAl2 undergoes a cubic to tetragonal distortion below 30 K in zero magnetic field.
- Applied magnetic fields (10 kOe) restore cubic symmetry by lifting the 4f crystal field splitting.
- Anomalously high nuclear Schottky specific heat was observed in PrAl2 compared to pure Pr metal.
Conclusions:
- The 4f crystal field splitting in the tetragonally distorted phase of PrAl2 is responsible for the unusual low-temperature phenomena.
- Understanding these phenomena provides insights into the behavior of rare earth magnetic materials.
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