Electrical Properties of Materials and Devices
The research conducted in this laboratory is being addressed from four different viewpoints:
- potential application of a.c. impedance spectroscopy as an NDT tool for microstructural characterization with supporting evidence from SEM, TEM, STM, AFM, X-ray, SAXS, SANS, FTIR, BET, etc.
- modeling of electrical properties using equivalent circuits, effective medium models, percolation behavior as well as finite element models,
- improved processing of electronic ceramics for better compatibility with semiconductor processing,
- improved understanding of the role of dopants, film thickness, presence of interfacial layers as well as the effect of particle size, particle shape and distribution on the resultant electrical behavior and the consequent processing-microstructure-property correlations in a variety of materials.
Most of the research in this area is being carried out within this facility although some research requires the use of metallography labs at MSE, the cleanroom facilities of the Microelectronics Research Center as well as National Facilities such as the Advanced Photon Source at Argonne National Labs and others. Processing equipment used includes standard ceramic techniques such as dry pressing, sol-gel processing of thin films as well as photolithography for microcircuit fabrication. Profilometers, ellipsometers, reflectance and photoluminescence spectrometers are used for film thickness and optical properties determination. For electrical testing, a variety of instruments are available for determining dielectric constants, quality factors, dissipation factors, inductances as well as impedance, resistivity and conductivity of all classes of materials. Measurements may be carried out at room temperature, in a low temperature cryostat(10K-450K), in moderate temperature furnaces(-80C to 200C) and in high temperature furnaces (25C to 1000C) for frequencies ranging from mHz up to GHz. A homemade humidity controlled chamber is also available for testing under different humidity conditions.
Electrical testing equipment includes:
Hewlett Packard 4192A Impedance analyzer, Agilent Technologies E4991A RF Impedance Analyzer, Solartron 1260 Impedance Analyzer, Solartron 1296 Dielectric Interface, EG&G 310 Impedance Analyzer, GenRad 1689A Impedance Analyzer, Polyplus Impedance Analyzer, General Radio 1615 Capacitance Bridge, Andeen-Hagerling Capacitance Meter, Keithley 617 Electrometer, Keithley 220 & 228 Current Sources, Keithley 181 Nanovoltmeter, RT66 Ferroelectric Testing System, High Voltage Interface and Source, a large variety of test fixtures and a Probe Station.
Current Research Projects:
- Electrical Properties and Modeling of Polymer and Ceramic Matrix Insulator-Conductor Composites
- Microstructural Evolution of Metallic Alloys Using Electrical Methods: mechanical deformation induced and thermally induced
- Structure-Property Relationships in Conducting Polymers
- Processing, Characterization and Applications of Porous Materials
- Electrochemical Characterization of Biomedical Implant Materials
For more information, please contact:
Rosario A. Gerhardt
Rooms 261and 266
J. Erskine Love Building