青岛科技大学主页平台管理系统 chenkezheng--Home-- Discovery of superparamagnetism in sub-millimeter-sized magnetite porous single crystals

陈克正

Professor

Supervisor of Doctorate Candidates

Supervisor of Master's Candidates

Date of Birth:1965-10-27

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Discovery of superparamagnetism in sub-millimeter-sized magnetite porous single crystals

Release time:2021-03-15 Hits:

Key Words:Magnetite; Superparamagnetism; Single crystal; Porous; Molecular field theory

Abstract:In this work, sub-millimeter-sized magnetite porous single crystals were found to exhibit unique superparamagnetism rather than the known ferrimagnetism. This superparamagnetism was intimately related to the hydrothermal formation process, during which high lattice stress of ca. 6 GPa and large lattice strain of ca. -1.21 x 10(-2) would change the exchange constants of alpha, beta, and nu to concurrently meet criterions of (i) nu(1) = nu(2) = beta, (ii) alpha(1) = alpha(2) = alpha, and (iii) alpha beta = 1. These criterions, deduced from the molecular-field theory, were proposed to be the general transition conditions for any ferrimagnetic material exhibiting superparamagnetism when their size was beyond their superparamagnetic size limit. (C) 2016 Elsevier B.V. All rights reserved.

Volume:380

Issue:41

Translation or Not:no

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