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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Metallic state in cubic FeGe beyond its quantum phase transition.
P Pedrazzini1, H Wilhelm, D Jaccard
1DPMC, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
Physical Review Letters
|March 16, 2007
Summary
High pressure suppresses the helical order in cubic FeGe, with deviations from quantum criticality observed. The metallic state persists, challenging standard transition models.
Area of Science:
- Condensed Matter Physics
- Materials Science
- High-Pressure Physics
Background:
- The cubic modification of iron germanium (FeGe) exhibits long-wavelength helical magnetic order.
- Understanding the behavior of magnetic materials under extreme conditions like high pressure is crucial for fundamental physics and potential applications.
Purpose of the Study:
- To investigate the effects of high pressure on the electrical resistivity and structural properties of cubic FeGe.
- To determine the pressure-induced changes in the magnetic ordering and ground state of FeGe.
Main Methods:
- Electrical resistivity measurements under varying high pressures.
- Structural investigations using X-ray diffraction or similar techniques.
- Analysis of magnetic phase transitions and deviations from theoretical models.
Main Results:
- The helical magnetic order in FeGe is suppressed at a critical pressure (p(c)) around 19 GPa.
- An anomaly (T(X)(p)) and non-Fermi-liquid behavior observed above p(c) suggest a non-standard quantum critical phase transition.
- Band-structure calculations, including zero-point motion, successfully describe the metallic ground state at high pressures.
- Discontinuous changes in interatomic distances near the magnetic phase line were observed.
Conclusions:
- The suppression of magnetic order in FeGe under pressure does not align with conventional quantum critical transition theories.
- The metallic ground state's persistence is explained by including zero-point motion in theoretical models.
- Structural changes near the magnetic transition line indicate complex interplay between magnetism and lattice structure.
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