Intrinsic instability and entropy stabilization of grain boundaries

Journal Article · Mon Jul 30 04:00:00 EDT 1990 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.65.610· OSTI ID:6824471

Fecht, H J ^[1]

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1. W. M. Keck Laboratory of Engineering Materials, California Institute of Technology, Pasadena, CA (USA)

A simple method is proposed to describe the thermodynamic properties of disordered grain boundaries in nanocrystalline metals and semiconductors. Based on a free-volume approach at negative pressure of the universal equation of state, the maximum free volume, thermal expansion coefficient, specific-heat capacity, and excess enthalpy, entropy, and free energy of grain boundaries are derived from well-known thermodynamic relationships. The results show good agreement with available experimental data and suggest an intrinsic mechanical instability of a nanograin boundary (Gibbs instability) accompanied by divergences of {alpha} and {ital c}{sub {ital p}}, and the possibility of an entropy stabilization of nanograin boundaries.

• DOE Contract Number: FG03-86ER45242
• OSTI ID: 6824471
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 65:5; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
360603* -- Materials-- Properties
CALCULATION METHODS
CORRELATIONS
CRYSTAL STRUCTURE
DATA
ELEMENTS
ENERGY
ENTHALPY
ENTROPY
EXPANSION
FREE ENERGY
GRAIN BOUNDARIES
HIGH TEMPERATURE
INFORMATION
MATERIALS
MEDIUM TEMPERATURE
METALS
MICROSTRUCTURE
NUMERICAL DATA
PHYSICAL PROPERTIES
RANDOMNESS
SEMICONDUCTOR MATERIALS
SPECIFIC HEAT
STABILIZATION
THEORETICAL DATA
THERMAL EXPANSION
THERMODYNAMIC PROPERTIES
VERY HIGH TEMPERATURE