Van der Waals magnet VI_(3) demonstrates intriguing magnetic properties that render it great for use in various applications.However,its microscopic magnetic structure has not been determined yet.Here,we report neutro...Van der Waals magnet VI_(3) demonstrates intriguing magnetic properties that render it great for use in various applications.However,its microscopic magnetic structure has not been determined yet.Here,we report neutron diffraction and susceptibility measurements in VI_(3) that revealed a ferromagnetic order with the moment direction tilted from the c-axis by ~36° at 4 K.A spin reorientation accompanied by a structure distortion within the honeycomb plane is observed,before the magnetic order completely disappears at TC=50 K.The refined magnetic moment of ~1.3μB at 4 K is much lower than the fully ordered spin moment of 2μB/V^(3+),suggesting the presence of a considerable orbital moment antiparallel to the spin moment and strong spin-orbit coupling in VI_(3).This results in strong magnetoelastic interactions that make the magnetic properties of VI_(3) easily tunable via strain and pressure.展开更多
In this paper neutron diffraction experiments were performed for Fe-substituted Mn12 in order to determine the sites of Fe atoms. The results of structure refinements for the sample with our accessed highest Fe conten...In this paper neutron diffraction experiments were performed for Fe-substituted Mn12 in order to determine the sites of Fe atoms. The results of structure refinements for the sample with our accessed highest Fe content showed that all Fe atoms occupied Mn（3） sites in the Mn12 skeleton. The x-ray absorption fine structure experiments as well as multiple scattering simulations gave the same result. Thus we concluded that Fe atoms only occupied Mn（3） sites. This conclusion also means that Fe-substituted Mn12 series only includes the four single-molecule magnets of [Mn12-xFexO12（CH3COO）16（H2O）4]·2CH3COOH·4H2O （x = 1, 2, 3, and 4）, denoted by Mn11Fe1, Mn10Fe2, MngFe3, and Mn8Fe4, respectively.展开更多
This paper investigates the single-molecule magnets of pure and Cr/Fe-doped Mn12-Ac. The components of the mixed crystals are identified by AC susceptibility technique. The ground-state spin and anisotropy parameters ...This paper investigates the single-molecule magnets of pure and Cr/Fe-doped Mn12-Ac. The components of the mixed crystals are identified by AC susceptibility technique. The ground-state spin and anisotropy parameters of doped Mn12-Ac are obtained： （i） MnllCr-Ac （S=19/2, D=0.62K, B=0.0009K, A=63K）, and （ii） Mn11Fe-Ac （S=21/2, D=0.39 K, B=0.001 K, △=55 K）. The single-ion origin of the magnetic anisotropy is discussed.展开更多
The quantum tunnelling of magnetization （QTM） in single crystals of the single molecule magnet （Mn1-xCrx）12- Ac （x=0, 0.03, 0.04, 0.05） has been investigated. In comparison with its parent Mnl2-Ac, a greater rat...The quantum tunnelling of magnetization （QTM） in single crystals of the single molecule magnet （Mn1-xCrx）12- Ac （x=0, 0.03, 0.04, 0.05） has been investigated. In comparison with its parent Mnl2-Ac, a greater rate of magnetization relaxation and a lower effective potential-energy barrier have been observed in Cr-doping samples. This modulation of QTM due to the Cr-doping could be attributed to the small change of Sz due to the smaller spin of Cr itself and additional intrinsic but distributed transverse and longitudinal anisotropy raised by a subtle change of the local environment in the magnetic Mn12 core.展开更多
A new single-molecule magnet [Mn11Fe1O12 （CH3COO）16（H2O）4]·2CH3COOH·4H2O （Mn11Fe1） has been synthesized. The structure has been studied by the single crystal x-ray diffraction. The difference of Jahn-T...A new single-molecule magnet [Mn11Fe1O12 （CH3COO）16（H2O）4]·2CH3COOH·4H2O （Mn11Fe1） has been synthesized. The structure has been studied by the single crystal x-ray diffraction. The difference of Jahn-Teller distortion between Fe^3＋ and Mn^3＋ ion reveals that Fe^3＋ ion substitutes for Mn^3＋ ion on the Mn（3） sites in the Mn12 skeleton. The temperature dependence of the magnetization gives a blocking temperature TB=1.9K for Mn11Fe1. Based on the magnetization process analysis of the crystal at T=2K, we suggest that Mn11Fe1 has the ground state with a total spin S=11/2.展开更多
基金Supported by the Innovation Program of Shanghai Municipal Education Commission(Grant No.2017-01-07-00-07-E00018)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)+1 种基金the National Natural Science Foundation of China(Grant No.11874119)the support of U.S.DOE BES Early Career Award No.KC0402020 under Contract No.DE-AC05-00OR22725。
文摘Van der Waals magnet VI_(3) demonstrates intriguing magnetic properties that render it great for use in various applications.However,its microscopic magnetic structure has not been determined yet.Here,we report neutron diffraction and susceptibility measurements in VI_(3) that revealed a ferromagnetic order with the moment direction tilted from the c-axis by ~36° at 4 K.A spin reorientation accompanied by a structure distortion within the honeycomb plane is observed,before the magnetic order completely disappears at TC=50 K.The refined magnetic moment of ~1.3μB at 4 K is much lower than the fully ordered spin moment of 2μB/V^(3+),suggesting the presence of a considerable orbital moment antiparallel to the spin moment and strong spin-orbit coupling in VI_(3).This results in strong magnetoelastic interactions that make the magnetic properties of VI_(3) easily tunable via strain and pressure.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10375088 and 10505029）. Acknowledgment The authors thank Dr Denis Sheptyakov at PSI for much support of the neutron diffraction experiments.
文摘In this paper neutron diffraction experiments were performed for Fe-substituted Mn12 in order to determine the sites of Fe atoms. The results of structure refinements for the sample with our accessed highest Fe content showed that all Fe atoms occupied Mn（3） sites in the Mn12 skeleton. The x-ray absorption fine structure experiments as well as multiple scattering simulations gave the same result. Thus we concluded that Fe atoms only occupied Mn（3） sites. This conclusion also means that Fe-substituted Mn12 series only includes the four single-molecule magnets of [Mn12-xFexO12（CH3COO）16（H2O）4]·2CH3COOH·4H2O （x = 1, 2, 3, and 4）, denoted by Mn11Fe1, Mn10Fe2, MngFe3, and Mn8Fe4, respectively.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10505029 and 10375088)
文摘This paper investigates the single-molecule magnets of pure and Cr/Fe-doped Mn12-Ac. The components of the mixed crystals are identified by AC susceptibility technique. The ground-state spin and anisotropy parameters of doped Mn12-Ac are obtained： （i） MnllCr-Ac （S=19/2, D=0.62K, B=0.0009K, A=63K）, and （ii） Mn11Fe-Ac （S=21/2, D=0.39 K, B=0.001 K, △=55 K）. The single-ion origin of the magnetic anisotropy is discussed.
基金Project supported by the National Natural Science Foundation of China （Grant No 10505029）.
文摘The quantum tunnelling of magnetization （QTM） in single crystals of the single molecule magnet （Mn1-xCrx）12- Ac （x=0, 0.03, 0.04, 0.05） has been investigated. In comparison with its parent Mnl2-Ac, a greater rate of magnetization relaxation and a lower effective potential-energy barrier have been observed in Cr-doping samples. This modulation of QTM due to the Cr-doping could be attributed to the small change of Sz due to the smaller spin of Cr itself and additional intrinsic but distributed transverse and longitudinal anisotropy raised by a subtle change of the local environment in the magnetic Mn12 core.
基金Project supported by the National Natural Science Foundation of China （Grant No 10375088）.
文摘A new single-molecule magnet [Mn11Fe1O12 （CH3COO）16（H2O）4]·2CH3COOH·4H2O （Mn11Fe1） has been synthesized. The structure has been studied by the single crystal x-ray diffraction. The difference of Jahn-Teller distortion between Fe^3＋ and Mn^3＋ ion reveals that Fe^3＋ ion substitutes for Mn^3＋ ion on the Mn（3） sites in the Mn12 skeleton. The temperature dependence of the magnetization gives a blocking temperature TB=1.9K for Mn11Fe1. Based on the magnetization process analysis of the crystal at T=2K, we suggest that Mn11Fe1 has the ground state with a total spin S=11/2.
