Superparamagnetism in ZnFe_2O_4 Induced by High Pressure Squeezing

概要

論文の詳細を見る
It was found that ZnFe_2O_4 exhibited a superparamagnetic behavior due to the formation of magnetic clusters inside the specimen when squeezed by an anvil under the pressure of (1∼3)×10^4kg/cm^2 at room temperature. From the analyses of the magnetization curves, the mean magnetic moment of a cluster was calculated to be of the order of 10^<-17>emu and its temperature dependence was also determined from the initial susceptibility. The number of the clusters involved in 1 gr of the squeezed ZnFe_2O_4 was about 10^<17> which varies almost proportionally with applied pressure. It is suggested that the magnetic cluster may be the stacking fault formed by squeezing in which some ferric ions are slipped into tetrahedral sites during the crystal slip. The superparamagnetism disappears gradually by annealing above 400℃ and the activation energy for the recovery was about 1.7eV.
社団法人応用物理学会の論文
1964-06-15