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Pressure effect on low‐temperature remanence of multidomain magnetite: Change in demagnetization temperature
Author(s) -
Sato Masahiko,
Yamamoto Yuhji,
Nishioka Takashi,
Kodama Kazuto,
Mochizuki Nobutatsu,
Tsunakawa Hideo
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl050402
Subject(s) - remanence , magnetite , demagnetizing field , geology , rock magnetism , isothermal process , saturation (graph theory) , materials science , mineralogy , magnetic field , magnetization , thermodynamics , physics , quantum mechanics , paleontology , mathematics , combinatorics
We have conducted the first in‐situ thermal demagnetization experiments on low‐temperature remanences of magnetite under high pressure up to 0.7 GPa, to investigate the pressure dependence of the demagnetization temperature ( T d ) defined as rapid decreases in the remanences. A sample of multidomain magnetite particles was set up in the piston‐cylinder‐type high‐pressure cell specially designed for an MPMS. We conducted zero‐field warming (ZFW) on (1) saturation isothermal remanent magnetizations imparted at 20 K and (2) remanences given by field cooling from 300 to 20 K. Our measurements show a clear decrease in T d with pressure at a rate of −2.9 K/GPa, although a positive rate was inferred by the previous study. Combining with other transition data of physical properties, sharp declines in low‐temperature remanences around 120 K during ZFW are considered as one of the physical property changes associated with the Verwey transition.