Low-energy magnetic excitations in Co/CoO core/shell nanoparticles

Uniform excitations in magnetic nanoparticles

We present a short review of the magnetic excitations in nanoparticles below the superparamagnetic blocking temperature. In this temperature regime, the magnetic dynamics in nanoparticles is dominated by uniform excitations, and this leads to a linear temperature dependence of the magnetization and the magnetic hyperfine field, in contrast to the Bloch T(3/2) law in bulk materials. The temperat...

Uniform magnetic excitations in nanoparticles

Low - energy spin excitations in the molecular magnetic cluster

– We report an Inelastic Neutron Scattering (INS) study of the fully deuterated molecular compound K6[V IV 15 As6O42]·9D2O (V15). Due to geometrical frustration, the essential physics at low temperatures of the V15 cluster containing 15 coupled V 4+ (S=1/2) is determined by three weakly coupled spin-1/2 on a triangle. The INS spectra at low-energy allow us to directly determine the effective ex...

Low-energy excitations in NaV2O5.

In the (ab) polarized Raman scattering spectra of NaV2O5 single crystals, measured with 647.1 nm laser line at T < Tc, we found two modes at 86, and 126 cm not previously reported. These two modes, together with 66, and 106 cm modes, make an array of four low-energy equidistant modes below the energy onset of the continuum at about 132 cm. All four modes are strongly suppressed by increasing Na...

Low - Energy Excitations in an Incipient Antiferromagnet

We present fully self-consistent calculations in the fluctuation exchange approximation for the half-filled Hubbard model in 2D. A non-fermi liquid state evolves with decreasing temperature in this self-consistent model of coupled spin fluctuations and quasiparticles. The mean field phase transition to long-range antiferromagnetic order is suppressed and we find no evidence of a phase transitio...