Which type of charge carrier has greater mobility why and difference between ion mobility and diffusion coefficient?
Electrons typically have greater mobility compared to ions in a given medium. This is because electrons are much lighter than ions, and their movement is less hindered by collisions with other particles. The relationship between charge carrier mobility and mass is described by the Einstein relation.
Ion mobility and diffusion coefficient are related but represent different aspects of particle movement in a medium. Ion mobility is a measure of the average drift velocity of ions under the influence of an electric field. It is influenced by the charge and size of the ions. On the other hand, diffusion coefficient describes the rate of random motion of ions due to thermal energy, without the influence of an electric field.
In summary, electrons generally have greater mobility than ions due to their lighter mass. Ion mobility focuses on directed motion under an electric field, while diffusion coefficient relates to the random motion of particles in the absence of an external force.