Alumina diffusion barrier for sensing elements

Abstract

A sensing element for a temperature sensor including a base with a platinum meander applied thereto. An alumina diffusion barrier (ADB) covers the meander to provide protection against contamination and structural stabilization, wherein the alumina diffusion barrier is a contiguous polycrystalline layer fabricated from alumina and approximately 1% by weight of a rutile additive to be substantially devoid of network porosity. The contiguous polycrystalline layer includes grains with a typical grain size being in a range of 0.5-3 μm. A method for fabricating an alumina diffusion barrier includes the steps of: combining a nano-alumina and nano-rutile powder to create a formulation; applying the formulation to the platinum meander to form a layer; and sintering the layer to create a contiguous polycrystalline layer covering the platinum meander.

Dependencies are inferred from the claim text.