Date of Award

Summer 1964

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

First Advisor

Greener, Evan H.

Second Advisor

Hirthe, W. M.

Third Advisor

Richardson, Bobbie L.

Abstract

The present studies were undertaken as an attempt to determine the feasibility of developing and fabricating a solid state heating device whose properties enable unique application in the light appliance industry. Characteristically, this device must be self-limiting in nature so as to reach and maintain a temperature of approximately 325 degrees f. It must also be of sufficiently low resistance for conduction below the limiting temperature, and be of sufficiently high resistance above it to facilitate the self-limitation. The use of barium titanate is indicated for this application as it undergoes a ferroelectric to paraelectric transformation at 250 degrees f. Also, its resistance, although prohibitively high in the pure state, can be reduced to a practical value by "doping," i.e., the addition of appropriate impurity cations substitutionally for either barium or titanium on their respective lattice sites. Variation of the Curie point temperature can also be attained by addition of these doping elements. Consequently, in an effort to attain such a device, suitable "doping" elements and fabrication techniques must be determined.

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