Chiral mesostructured hematite with temperature-independent magnetism due to spin confinement  

作　　者：Baiwen Zhang Jing Ai Yingying Duan Te Bai Lu Han Shunai Che 

机构地区：[1]School of Physics Science and Engineering,Tongji University,Shanghai 200092,China [2]School of Chemistry and Chemical Engineering,Tongji University,Shanghai 200092,China [3]Wuxi Vocational College of Science and Technology,Wuxi 214028,China [4]School of Chemistry and Chemical Engineering,Frontiers Science Center for Transformative Molecules,State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Nano Research》2024年第3期2019-2024,共6页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21931008,21873072,21922304,and 21975184);the National Key R&D Program of China(No.2021YFA1200301);Fundamental Research Funds for the Central Universities,Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219);Natural Science Fund for Colleges and Universities in Jiangsu Province(No.22KJB150041);Wuxi"Taihu Light"Science and Technology Project-Basic Research(No.K20221067).

摘　　要：Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.

关 键 词：HEMATITE chiral mesostructure Dzyaloshinskii–Moriya interaction weak ferromagnetism antiferromagnetic material temperature-independent magnetism 

分 类 号：O62[理学—有机化学]