ChemInform Abstract: Competition Between the Direct Exchange Interaction and Superexchange Interaction in Layered Compounds LiCrSe2, LiCrTe2, and NaCrTe2with a Triangular Lattice.

ChemInform ◽  
2016 ◽  
Vol 47 (41) ◽  
Author(s):  
Shintaro Kobayashi ◽  
Hiroaki Ueda ◽  
Chishiro Michioka ◽  
Kazuyoshi Yoshimura
Keyword(s):  
Exchange Interaction ◽  
Triangular Lattice ◽  
Superexchange Interaction ◽  
Layered Compounds ◽  
Direct Exchange

Magnetic Properties

2003 ◽  
Author(s):  
Toshiaki Enoki ◽  
Morinobu Endo ◽  
Masatsugu Suzuki
Keyword(s):  
Critical Temperature ◽  
Exchange Interaction ◽  
Three Dimensional ◽  
Ferromagnetic Layer ◽  
Magnetic Behavior ◽  
Interlayer Coupling ◽  
Spin Correlation ◽  
Layered Compounds ◽  
Metal Chlorides ◽  
Spin Order

Two-dimensional (2D) magnetic phase transition has been one of the major topics of condensed matter physics. There are many materials in which the magnetic ions are arranged in planes so that there is strong coupling between the spins within a plane, but only a weak coupling between spins in different planes. In materials such as transition metal chlorides (FeCl2, CoCl2, and NiCl2) there is a strong ferromagnetic coupling within the planes and a coupling between planes which is weaker by a factor of 10 or so and antiferromagnetic. In more complicated ferromagnetic layer compounds such as (CH3 NH3)2 CuCl4, the interlayer coupling is down by a factor of more than a thousand. There are also many materials, such as Rb2MnF4, Rb2CoF4, and K2CoF4, in which the coupling within the plane is antiferromagnetic. This can result in a very much reduced coupling between the planes, since one spin may have four spins in the next plane which are at an equal distance, and their effects cancel out. As a result, the coupling between layers in this material is down by a factor of 106. In these layered compounds the magnetic behavior is only 2D-like at a certain distance away from the critical temperature. Close to the critical temperature, there is a long-range correlation of the spins within the layer and such a correlated region will interact between one layer and the next even if the coupling between individual spins is weak, since many spins can contribute coherently. Thus the spin order near the critical temperature is essentially three-dimensional (3D). What condition should be required for the occurrence of a real 2D spin order in layered magnetic systems? We consider a system consisting of only two magnetic layers separated by a distance. The effective interplanar exchange interaction J'eff is given by J'(ξa)2, but not by J', where ξa is the in-plane spin correlation length and J' is the interplanar exchange interaction. If ξa diverges on approaching a critical temperature, the effective interplanar exchange interaction J'eff becomes comparable with the intraplanar exchange interaction J.

scholarly journals Mixed-cation driven magnetic interaction of interstitial electrons for ferrimagnetic two-dimensional electride

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Seung Yong Lee ◽  
Joonho Bang ◽  
Hyun Yong Song ◽  
Byung Il Yoo ◽  
Yeongkwan Kim ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Degrees Of Freedom ◽  
Interlayer Space ◽  
Magnetic Interaction ◽  
Spin States ◽  
Two Dimensional ◽  
Direct Exchange ◽  
Mixed Cation ◽  
Layered Crystals ◽  
Condensed Matters

AbstractMagnetism of pure electrons is fundamental for understanding diverse magnetic phenomena in condensed matters but has not been fully investigated in experiments due to the lack of a tractable model system. Such an exotic material necessitates an exclusive magnetic interaction of electrons being devoid of orbital and lattice degrees of freedom. Here, we report the two-dimensional mixed-cation [YGdC]2+∙2e− electride, showing ferrimagnetic nature from the direct exchange interaction of magnetic interstitial electrons in interlayer space. We identify that magnetic interstitial electrons are periodically localized in octahedral and tetrahedral cavities between 2D cationic Y2−xGdx arrays. The mixed configuration of non-magnetic and magnetic cations in cavities induces divergent spin states and interactions of magnetic interstitial electrons, in which their direct exchange interaction overwhelms the interactions with magnetic cations, triggering the ferrimagnetic spin-alignment. This discovery facilitates further exploration of magnetic electrides and nurtures the study of two-dimensional magnetism of layered crystals and electron phases.

Sign in / Sign up

Export Citation Format

Share Document