The probe may be applied in several areas for the following determinations:

AREA	PROPERTIES
Solid-State Chemistry	Defect chemistry, non-stoichiometry, chemical diffusion, gas/solid reactions
Solid-State Physics	Charge transport, semiconducting properties, bi-dimensional structural transitions
Materials Science	Equilibration kinetics, phase transitions in the boundary layer, electronic structure
Metallurgy	Mechanism and kinetics of oxidation and reduction processes
Catalysis	Mechanism and kinetics of chemisorption and catalytic processes
Sensorics	Determination of the sensing signal at the gas/solid interface

 

SPECIFICATION
Temperature	RT - 1200 K
Gas Environment	Static/Dynamic
.
SIZE
Height	1000 mm
Base	400x400 mm
Weight	21 kG
Specimen's Size	Approx 10x10x2mm
Vibration Frequency	30 Hz - 100 KHz
Accuracy	± 0.5 mV

 

High Temperature Kelvin Probe: CONSTRUCTION AND PERFORMANCE

The HTKP-2000 and the ancillary equipment are shown, schematically, in Figure 1. The probe incorporates the following integral components: (1) vibrating system, (2) vibrating capacitor, and (3) tuning system (Figures 2 and Figures 3). The vibrating capacitor is formed of a specimen located on support and upper reference electrode. The electrode is put into vibrations using piezoceramic element. The distance between the capacitor plates (about 0.1 - 0.2 mm) is tuned using a micrometer attached to the sample support.

A tube-type furnace is located in the middle part (at the sample level). Upper and lower water coolers aim at preventing the upper and lower parts against heating. Gas inlet and outlet are connected to a gas flow system. The probe is gas tightened by two fringes. The specimen is located on a support. A rack allows to remove the lower part of the probe and to replace the specimen. Performance of the probe and its applications were reported in refs. [1-3].

High Temperature Kelvin Probe: ANCILLARY EQUIPMENT

Additional equipment items required for HTKP-2000 include: high voltage amplifier, voltmeter, frequency generator, integrator, oscilloscope, chart recorder, personal computer, temperature controllers, lock-in amplifier, scanner, gas-flow system, and oxygen sensor.

Figure 1. The HTKP-2000 and ancillary equipment

 

High Temperature Kelvin Probe: WHY SURFACE PROPERTIES AT ELEVATED TEMPERATURES ARE IMPORTANT.

Properties of materials interfaces, such as surfaces and grain boundaries, are entirely different from those of the bulk phase [4,5]. It appears that most of materials properties are strongly influenced or even determined by interfaces. Concordantly, interfaces hold the key to tailoring materials properties for specific industrial applications.

There is an increasing need to understand interface properties and phenomena in situ during processing of materials at elevated temperatures and controlled gas phase composition. Application of the most of surface sensitive tools based on electron and ion spectroscopy, such as XPS, SIMS, ISS and LEED, is limited to room temperature (when materials are quenched) and high vacuum (when surface composition of compounds are different than those under atmospheric pressure).

The HTKP-2000 is a very powerful tool in hands of solid state chemists and materials scientists that allows to have an insight into the unknown world of surface properties at elevated temperatures under atmospheric pressure and, consequently, in understanding the role of these phenomena in the formation of the materials that are required for specific applications.

For a complete technical description and features of the High Temperature Kelvin Probe - HTKP - 2000 click here: High Temperature Kelvin Probe (HTKP - 2000)

For further information please contact

Mr. Ross K. Druitt
Managing Director of Sialon Ceramics Pty. Ltd. and Wallarah Minerals Pty. Ltd.
130 Tall Timbers Rd, Doyalson North, NSW 2262, Australia
Tel. +61 2 4358 4994; Fax. +61 2 4358 1348

Sialon Ceramics ABN: 57 002 988 543; Wallarah Minerals ABN: 77 002 503 399

Email:

office@sialon.com.au