Thermoremanent and chemical magnetization of exsolution products of nanosized titanomagnetites

Resumo

Based on the theory of two-phase interacting nanoparticles, the formation of thermoremanent and chemical remanent magnetization in nanosized titanomagnetites is modeled. It is shown that the value of thermoremanent magnetization barely depends on the degree of titanomagnetite exsolution whereas, chemical remanent magnetization which emerges during the exsolution increases up to at most the value of thermoremanent magnetization. The values of the ratio of thermoremanent to ideal magnetization, R_t, fall within the limits 0.8 ≤ R_t ≤ 1. The analogous ratio of chemical remanent magnetization to the ideal R_c are below R_t at all stages of the exsolution. Besides, the magnetic interaction between the nanoparticles reduces the values of thermoremanent and chemical magnetization but barely affects the ratio.