Effect of magnetic exchange, double exchange, vibronic coupling, and asymmetry on magnetic properties in d(2)-d(3) mixed-valence dimers

摘要

The effect of magnetic exchange, double exchange, vibronic coupling, and asymmetry on magnetic properties of d(2)-d(3) systems is discussed. The temperature-dependent magnetic moment was calculated with the semiclassical adiabatic approach. The results show that the vibronic coupling from the out-of-phase breathing vibration on the metal sites (Piepho, Krausz, and Schatz [PKS] model) and the vibronic coupling from the stretching vibration between the metal sites (P model) favor the localization and delocalization of the "extra" electron in mixed-valence dimers, respectively. The magnetic properties are determined by the interplay among magnetic exchange, double exchange, and vibronic coupling. The results obtained by analyzing d(2)-d(3) systems can be generalized to other full delocalized dinuclear mixed valence systems with a unique transferable electron. (c) 2005 Wiley Periodicals, Inc.