Infrared properties of thin Pt/Al sup 2 O sup 3 granular metal-insulator composite films
The reflection of mid- and near-infrared radiation (400-15000 cm-1) by thin Pt/A1203 cermet films was measured using Fourier transform spectrometer. The data were compared with predictions of three models for the effective optical constants of heterogeneous materials: Maxwell-Garnet, Bruggeman, and a simplified version of a probabilistic growth model due to Sheng. Sheng's model provides the best description of the data over the complete range of metallic volume fraction. This result is expected based on the most likely topology of the films and is in agreement with other work on similar at higher frequencies. The relationship between the microstructural topology, the optical properties of a heterogeneous system, and their description by an homogeneous effective dielectric function has been made clear in recent years. The prediction of the optical response of a granular metal/insulator composite material over the complete range of composition provides an especially stringent challenge to effective medium theories.
- Research Organization:
- Pittsburgh Univ., PA (United States). Dept. of Physics and Astronomy
- OSTI ID:
- 5470859
- Report Number(s):
- AD-A-234327/5/XAB; CNN: N00014-85-K-0808
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM OXIDES
OPTICAL PROPERTIES
PLATINUM ALLOYS
CERAMICS
CERMETS
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
ELECTRICAL INSULATORS
FILMS
FOURIER TRANSFORMATION
INFRARED RADIATION
MATHEMATICAL MODELS
METALS
MICROSTRUCTURE
NEAR INFRARED RADIATION
PLATINUM
PROBABILITY
RESPONSE FUNCTIONS
SPECTROMETERS
TOPOLOGY
ALLOYS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CRYSTAL STRUCTURE
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUIPMENT
EVALUATION
FUNCTIONS
INTEGRAL TRANSFORMATIONS
MATERIALS
MATHEMATICS
MEASURING INSTRUMENTS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
PLATINUM METALS
RADIATIONS
TRANSFORMATIONS
TRANSITION ELEMENTS
360204* - Ceramics
Cermets
& Refractories- Physical Properties