How do ceramic thermistors work? I can hardly find any information..  and the few I got from my script is not revealing so much:

Electrons are strongly bounded (ceramics) – electrons are transported from a bound state into an energetically similar vicinal state by thermal activation (hole transport).


Is it just that? For me, this could also be applied to a semiconductor resistor.
 A: Ceramic resistors are not generally dependant on mechanisms shown in your diagram. There are several processes which produce what might be called "ceramic resistors" but the most usual are "CERMET" (ceramic-metal) resistors consisting of a sintered electrically non-conductive material with distributed conductive metal particles. The metal provides a large number of interlinked multiple paths through the material resulting in a strong, high temperature non inductive resistor.
From here - cermets.


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*Here's the structure of a typical cermet made from particles of ceramic alumina (red), each of which is surrounded by platinum metal (blue). Although electricity doesn't normally flow through a ceramic, it can flow through a cermet (yellow arrowed line) by following a circuit through the platinum. Artwork based on a drawing from US Patent 4,183,746: Cermets by Stephen L. Pearce and Gordon L. Selman, Johnson, Matthey & Co., Limited, courtesy of US Patent and Trademark Office.

Some characteristics [ceramic resistors] from "US Resistor" (http://www.usresistor.com/index.php/materials/ceramic-resistors)

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*Ceramic resistors are manufactured from a sintered body of ceramic material, with conductive particles distributed throughout the matrix, to produce a resistor that is 100% active and non-inductive.  Ceramic resistors are chemically inert.  They can withstand high-energy and high-voltages at high temperatures, such as those encountered in the protection of high voltage surge equipment, discharge banks, and in high frequency radiation suppression.  Electrical characteristics are as follows:

Patent US4183746 cermets - a number of the citations are very relevant.
See also patent High-temperature-resistant cermet material and preparation method thereof
