A large family of chromium(iii) dimers has been synthesised and magneto-structurally characterised using a combination of carboxylate and diethanolamine type ligands. The compounds have the general formula [Cr2(R1-deaH)2(O2CR2)Cl2]Cl where R1 = Me and R2 = H (1), Me (2), CMe3 (3), Ph (4), 3,5-(Cl)2Ph (5), (Me)5Ph (6), R1 = Et and R2 = H (7), Ph (8). The compound [Cr2(Me-deaH)2Cl4] (9) was synthesised in order to study the effect of removing/adding the carboxylate bridge on the observed magnetic behaviour. Direct current (DC) magnetic susceptibility measurements showed ferromagnetic (FM) exchange interactions between the Cr(iii) centres in the carboxylate bridged family with coupling constants in the range +0.37 < J < +8.02 cm-1. Removal of the carboxylate to produce the dialkoxide-bridged compound 9 resulted in antiferromagnetic (AFM) exchange between the Cr(iii) ions. DFT calculations reveal the ferromagnetic exchange is the result of an orbital counter-complementarity effect occuring upon introduction of the bridging carboxylate.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c8dt01963k | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Role of Competing Magnetic Exchange on Non-Collinear to Collinear Magnetic Ordering and Skyrmion Stabilization in Centrosymmetric Hexagonal Magnets.
ACS Nano
January 2025
School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050, India.
Topological magnetic skyrmions with helicity state degrees of freedom in centrosymmetric magnets possess great potential for advanced spintronics applications and quantum computing. Till date, the skyrmion study in this class of materials mostly remains focused to collinear ferromagnets with uniaxial magnetic anisotropy. Here, we present a combined theoretical and experimental study on the competing magnetic exchange-induced evolution of noncollinear magnetic ground states and its impact on the skyrmion formation in a series of centrosymmetric hexagonal noncollinear magnets, MnFeCoGe.
View Article and Find Full Text PDFMagnetic phase transition and magnetocaloric effect in hexagonal MnCoGe alloys mediated by axial strain: a Monte Carlo study.
Phys Chem Chem Phys
January 2025
Department of Physics, College of Sciences, Northeastern University, Shenyang 110819, China.
Article Synopsis
- The study investigates how axial strain affects the magnetic properties of hexagonal MnCoGe alloys, focusing on the transition from ferromagnetic to antiferromagnetic states.
- It combines first-principles calculations and Monte Carlo simulations to show that compressive strains stabilize ferromagnetism, while tensile strains lead to antiferromagnetism, with the transition temperature rising as compressive strain increases.
- The research identifies key magnetic exchange couplings and demonstrates that applying strain enhances magnetic stability and improves control over the magnetocaloric effect, with notable changes in magnetic entropy under a magnetic field.
Spin and valley dependent transport and tunneling magnetoresistance in irradiated ferromagnetic WSedouble barrier junctions.
Sci Rep
January 2025
College of Science, Xuchang University, Xuchang, 461000, China.
Spin and valley polarizations (P and P) and tunneling magnetoresistance (TMR) are demonstrated in the ferromagnetic/barrier/normal/barrier/ferromagnetic WSe junction, with the gate voltage and off-resonant circularly polarized light (CPL) applied to the two barrier regions. The minimum incident energy of non-zero spin- and valley-resolved conductance has been derived, which is consistent with numerical calculations and depends on the electric potential U, CPL intensity ΔΩ, exchange field h, and magnetization configuration: parallel (P) or antiparallel (AP). For the P (AP) configuration, the energy region with P = -1 or P = 1 is wider (narrower) and increases with ΔΩ.
View Article and Find Full Text PDFSelf-Intercalation as Origin of High-Temperature Ferromagnetism in Epitaxially Grown Fe_{5}GeTe_{2} Thin Films.
Phys Rev Lett
December 2024
Institute of Molecular Science, University of Valencia, Catedratico Jose Beltrán 2, 46980 Paterna, Spain.
The role of self-intercalation in 2D van der Waals materials is key to the understanding of many of their properties. Here we show that the magnetic ordering temperature of thin films of the 2D ferromagnet Fe_{5}GeTe_{2} is substantially increased by self-intercalated Fe that resides in the van der Waals gaps. The epitaxial films were prepared by molecular beam epitaxy and their magnetic properties explored by element-specific x-ray magnetic circular dichroism that showed ferromagnetic ordering up to 375 K.
View Article and Find Full Text PDFPermanent Electride Magnets Induced by Quasi-Atomic Non-Nucleus-Bound Electrons.
Adv Mater
January 2025
Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
Article Synopsis
- Interstitial quasi-atomic electrons (IQEs) significantly influence the magnetism of crystalline electrides, with their own magnetic moments affected by nearby cations.
- Weak spin-orbit coupling and limited interactions prevent these systems from achieving hard magnetism, presenting a challenge for stronger magnetic properties.
- However, certain 2D electrides, like [ReC]·2e, exhibit permanent magnetism by creating a ferrimagnetic state and demonstrate high coercivity due to the interaction between Re-spin and IQE-spin lattices.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!