5 research outputs found
Heat capacity uncovers physics of a frustrated spin tube
We report on refined experimental results concerning the low-temperature
specific heat of the frustrated spin tube material [(CuCl2tachH)3Cl]Cl2. This
substance turns out to be an unusually perfect spin tube system which allows to
study the physics of quasi-one dimensional antiferromagnetic structures in
rather general terms. An analysis of the specific heat data demonstrates that
at low enough temperatures the system exhibits a Tomonaga-Luttinger liquid
behavior corresponding to an effective spin-3/2 antiferromagnetic Heisenberg
chain with short-range exchange interactions. On the other hand, at somewhat
elevated temperatures the composite spin structure of the chain is revealed
through a Schottky-type peak in the specific heat located around 2 K. We argue
that the dominating contribution to the peak originates from gapped magnon-type
excitations related to the internal degrees of freedom of the rung spins.Comment: 4+ pages, 6 figure
Supramolecular assembly of ligand-directed triangular {CuII 3Cl} clusters with spin frustration and spin-chain behaviour
Supramolecular assembly of ligand-directed triangular {CuII 3Cl} clusters with spin frustration and spin-chain behaviour
Linear, Trinuclear Cobalt Complexes with o-Phenylene-bis-Silylamido Ligands
Transamination of [Co{N(SiMe3)2}2]2 with C6H4(NHSiiPr3)2 gave the centrosymmetric trinuclear [{CoterN(SiMe3)2(μ-η-[o-C6H4(κNSiiPr3)2])}2Coint] ( 1 ) (Coter, Coint=terminal, internal Co, respectively), with 3-coordinate Coter, and Coint “sandwiched” between the o-phenylenes of the two ligands; experimental and computational data support CoII centres and ditopic o-amido-imino-cyclohexen-allyl ligands; magnetic studies reveal intermetallic ferromagnetic interactions and single-molecule magnet (SMM) character. One-electron reduction of 1 yielded the salt [K(18-crown-6)(THF)2][{CoterN(SiMe3)2(μ-η-[o-C6H4(κNSiiPr3)2])}2Coint] ( 4 ) with the anion isostructural to 1 . The centrosymmetric Fe complex [{FeterN(SiMe3)2(μ-η-[o-C6H4(κNSiiPr3)2])}2Feint] ( 5 ), analogous to 1 , was also obtained