Conduction in RuO₂-based thick films†

Electronic transport in RuO2-based thick film resistors at low temperatures

“…The essential features are that it assumes a small activation energy associated with electrostatic charging of conductive particles, and that impurities within the tunnel barriers act as resonant centres to increase the barrier transmission coefficienO ~ The model gives a low temperature dependence of the resistance of the form (4) where the first factor in brackets describes the temperature dependence of the tunnelling process at the junction, and the second term in brackets, representing a correction for small metallic particles, contains the electrostatic energy E required to add or remove an electron from a particle (the charging energy). The constant a depends on the barrier height and Rb is the barrier resistance at low temperatures if E is unimportant.…”

Microstructural Analysis and Transport Properties of RuO2-Based Thick Film Resistors

“…The reason for these behaviours of R(T ) and corresponding W (T ) and S(T ) is the most probably connected with the diffusion of Ru atoms or tiny RuO 2 particles from the surface of RuO 2 grains into the dielectric glass matrix and also additional diffusion of atoms from conductive Ag-Pd pads or Al 2 O 3 substrate [3,[5][6][7]. These diffused atoms can create impurity in-gap states in a very small energy gap of width ∼ kT around the Fermi level of the glass, and so lowers the activation energy for hopping (tunnelling).…”

“…Different transport mechanisms controlled by the microstructure of thick film resistors have been identified [3] [3,5,6].…”

RuO2-based Low Temperature Sensors with ?Tuned? Resistivity Dependencies

“…fast response, reasonable reproducibility, sufficient stability and suitable temperature coefficient of resistance at about room temperature. One of them, RuO 2 -based thick film resistor, furthermore appears as a very good secondary thermometer, mainly in the temperature range below 4.2 K. This is due to its relatively high temperature sensitivity remaining virtually insensitive on magnetic field [1][2][3][4][5].…”