Nuclear antiferromagnetism

Reaction of [Ni(acac)2(H20)2] with benzotriazolate (bta or a derivative thereof) gives a penta-nuclear compound [Ni5(OH)(bta)5(acac)4(H20)4].2258,2259 Its structure is composed of a tetrahedral arrangement of four six-coordinate Niir ions centered on the fifth, and the complex exhibits antiferromagnetic coupling with an intermediate spin [5 0, 5=1] ground state.2259 The ground... 

When I J is of the order of hundreds of wavenumbers, i.e., it is of the order of kT, then the excited S levels are not fully populated. In homodimers antiferromagnetically coupled, the ground state is diamagnetic (S = 0). If only one metal ion is sensed by the resonating nucleus, nuclear relaxation... 

Minkiewicz, V., and A. Nakamura Direct observation of Mn nuclear magnetic resonance in antiferromagnetic CsMnFj. Phys. Rev. 143, 361 (1966). 

The alternating spin magnetic moments in antiferromagnets such as NiO can be observed experimentally using neutron diffraction. Because neutrons have a magnetic moment, a neutron beam used for diffraction responds not only to the nuclear positions but also to the magnetic moments of the atoms. X-rays on the other hand... 

Several polymetallic systems experience magnetic coupling, either ferromagnetic or antiferromagnetic. Such magnetic coupling may affect the hyperfine shift and electron relaxation. Beneficial effects are always expected and observed on nuclear relaxation. A series of examples are discussed. 

The absolute value of J, which we have used all over the treatment within the Redfield limit, implies that the theory is the same for ferro- and antiferromagnetic coupling. When J kT, the sign of J is irrelevant for the nuclear shifts, the... 

The intermediate state in MnF2 in the neighbourhood of the spin-flop transition was studied by means of nuclear magnetic resonance [5] and antiferromagnetic resonance [12], [14]. 

Abstract Spatially-resolved NMR is used to probe antiferromagnetism in the vortex state of nearly optimally doped high-rc cuprate H2Ba2CuC>6+a (Tc = 85 K). The broadened 205Tl-spectra below 20 K and the temperature dependence of the enhanced nuclear spin-lattice relaxation rate 205 Tfl at the vortex core region indicate clear evidences of the antiferromagnetic order inside the vortex core ofTl2Ba2Cu06+J. 

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