Open AccessActivation Energy of Cation Migration in Titanomagnetites
Author(s) -
Creer K. M.,
Ibbetson Jill,
Drew W.
Publication year - 1970
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1970.tb06740.x
Subject(s) - spinel , curie temperature , magnetization , activation energy , basalt , homogeneous , condensed matter physics , magnetite , magnetic anomaly , geology , materials science , mineralogy , thermodynamics , geophysics , chemistry , magnetic field , geochemistry , ferromagnetism , physics , metallurgy , quantum mechanics
Summary Some basalts from the Azores Islands, containing homogeneous titanomagnetites, exhibit a rapid increase in magnetization when heated in air to about 400 °C. A new magnetic phase with a Curie point of about 540 °C is produced. By measuring the rate of increase in magnetization at different temperatures the activation energy of the chemical change involved has been calculated to be 0–5 eV per molecule, and it is suggested that this corresponds to migration of cations in the spinel lattice.