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Magnetostriction in aluminium‐substituted titanomagnetites 1
Author(s) -
Özdemir Özden,
Moskowitz Bruce M.
Publication year - 1992
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 - 10.1029/92gl02716
Subject(s) - magnetostriction , curie temperature , materials science , aluminium , saturation (graph theory) , crystallite , magnetization , analytical chemistry (journal) , magnetism , condensed matter physics , atmospheric temperature range , nuclear magnetic resonance , metallurgy , ferromagnetism , chemistry , magnetic field , thermodynamics , physics , mathematics , chromatography , quantum mechanics , combinatorics
Using the strain gauge technique, the magnetostriction constants λ S have been measured on sintered polycrystalline specimens of titanomagnetites with Fe 2.4‐δ Ti 0.6 A δ O 4 compositions (0.05 ≤ δ ≤ 0.20) in the temperature range between 25°C and T c . The cell‐edge, saturation magnetization, and Curie temperature decrease with increasing aluminium concentration. The room‐temperature λ S values are 95.7, 70.6, 52.9 and 25.2×10 −6 for δ=0.05, 0.10, 0.15 and 0.20 respectively. A linear relationship is found between the magnetostriction constant and the aluminium content at room temperature. The constant λ S (T) is proportional to approximately the third power of the saturation magnetization M S (T). The values of the index n in λ S (T) ∼ M S n (T) are 2.72, 3.16, 3.35 and 3.60 for δ=0.05, 0.10, 0.15 and 0.2 respectively. This if the first reported measurement of λ S (T) at elevated temperatures for A‐substituted titanomagnetites. Such data are urgently needed in theoretical and experimental magnetic domain structure studies in rock magnetism.