Development of highly inhomogeneous temperature profile within electrically heated alkali silicate glasses.

ABSTRACT: According to Joule's well-known first law, application of electric field across a homogeneous solid should produce heat uniformly in proportion to the square of electrical current. Here we report strong departure from this expectation for common, homogeneous ionic solids such as alkali silicate glasses when subjected even to moderate fields (~100 V/cm). Unlike electronically conducting metals and semiconductors, with time the heating of ionically conducting glass becomes extremely inhomogeneous with the formation of a nanoscale alkali-depletion region, such that the glass melts near the anode, even evaporates, while remaining solid elsewhere. In situ infrared imaging shows and finite element analysis confirms localized temperatures more than thousand degrees above the remaining sample depe

SUBMITTER: McLaren CT 

PROVIDER: S-EPMC6391379 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature