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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:31 |
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Conference: Bucharest University Faculty of Physics 2013 Meeting
Section: Solid State Physics and Materials Science
Title:
Automatic thermostat system for investigations of
the temperature dependence of the properties of materials
Authors:
Laurentiu Sufaru, Adrian Rotaru, Ciceron Berbecaru
Affiliation:
University of Bucharest, Faculty of Physics, Electricity and Magnetism, Solid-State Physics, Biophysics Department
Laboratory for Materials Science and Crystal Growth
Faculty of Physics, University of Bucharest
*Romanian Materials Science – Crystal Growth Society,
Bucharest – Magurele 077125, Romania
E-mail
laurentiu16@lycos.com ; rotarue@gmail.com ; berbecaru2ciceron@gmail.com
Keywords:
homemade thermostatic system, BaTiO3 – Ce doped ceramic, permittivity and losses.
Abstract:
Changing properties versus the temperature parameter is a feature common to most materials. Measuring the dependency must be carried out in various temperature regimes then, automatic temperature control systems are often used for this purpose. To build a suitable thermostat system, customized for measurement of electrical parameters of dielectric materials, was used an oven „Etuva 50” type and an „Toho 004” type temperature thermostat, both commercially available. The necessary changes were made to „Etuva 50”, mechanical and electrical, for compatibilization of components and to achieve the purpose. Controlled thermostatic tests, with variable slopes, showed a good linearity of temperature-time dependence for up to 200 oC. To measure the temperature dependence of the permittivity and, dielectric losses of an BaTiO3 ceramic material doped with Ce, to the thermostatic system was attached an automatic RLC bridge, type Hioki 3532-50 and a Keithley multimeter for temperature measurement. For electrical contacts it was build an adequate clamping system for samples, based on Pt pills inserted into a special mount. Experimental data were recorded automatically using a PC computer, an GPIB interface and an adequate software for further processing of the experimental data with specialized programs of "Origin" type. Investigations were carried out on an extended temperature, Troom – 160 oC and frequency ranges, 42 – 5 x 106 Hz, on heating and cooling the samples. Dielectric constant and losses presents typical dependences for ferroelectric materials, versus both temperature and frequency parameters and in the paraelectric phase.
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