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Updated: Apr 1, 2026
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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
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Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex
M I Dolz1, Y Fasano2, N R Cejas Bolecek2
1Departamento de Física, Universidad Nacional de San Luis and CONICET, 5700 San Luis, Argentina.
Physical Review Letters
|October 10, 2015
Summary
The study shows that vortex matter in nanocrystalline Bismuth Strontium Calcium Copper Oxide (Bi2Sr2CaCu2O8) maintains its solidification and order-disorder transitions even at small sizes. Entropy at the transition decreases with smaller sample sizes.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- Nanocrystalline materials exhibit unique properties due to their high surface-to-volume ratio.
- Vortex matter in superconductors is crucial for understanding flux pinning and critical current densities.
- Phase transitions in finite systems are essential for understanding bulk properties.
Purpose of the Study:
- To investigate the persistence of phase transitions in nanocrystalline vortex matter.
- To determine the effect of decreasing system size on vortex solidification and order-disorder transitions.
- To analyze the influence of surface-to-volume ratio on vortex binding energy.
Main Methods:
- Experimental observation of phase transitions in Bi2Sr2CaCu2O8.
- Analysis of vortex matter behavior at reduced system sizes (less than 100 vortices).
- Thermodynamic measurements to quantify entropy changes at transitions.
Main Results:
- Solidification and order-disorder first-order transition lines persist down to nanocrystalline sizes.
- Vortex solidification transition temperature remains unaffected by decreasing sample size.
- Entropy jump at the transition is depleted in smaller systems.
- Order-disorder transition field shifts upward with decreasing system size due to increased surface-to-volume ratio.
Conclusions:
- Nanocrystalline effects do not eliminate fundamental phase transitions in vortex matter.
- Surface-to-volume ratio significantly impacts vortex binding energy and transition fields in finite systems.
- Understanding these size-dependent effects is critical for designing superconducting devices.
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