Dmitry A. Sokolov

Neutron, Electron and X-ray Scattering Investigation of Cr1-xVx Near Quantum Criticality

The weakness of electron-electron correlations in the itinerant antiferromagnet Cr doped with V has long been considered the reason that neither new collective electronic states or even non Fermi liquid behaviour are observed when antiferromagnetism in Cr1 xVx is suppressed to zero temperature. We present the results of neutron and electron diffraction measurements of several lightly doped single crystals of Cr1 xVx in which the archtypal spin density wave instability is progressively suppressed as the V content increases, freeing the nesting-prone Fermi surface for a new striped charge instability that occurs at xc=0.037. This novel nesting driven instability relieves the entropy accumulation associated with the suppression of the spin density wave and avoids the formation of a quantum critical point by stabilising a new type of charge order at temperatures in excess of 400 K. Restructuring of the Fermi surface near quantum critical points is a feature found in materials as diverse as heavy fermions, high temperature copper oxide superconductors and now even elemental metals such as Cr.

Crystalline electric fields and the ground state of Ce3Rh4Pb13

We have succeeded in synthesizing of single crystals of a new intermetallic compound, Ce

Neutron diffraction in a model itinerant metal near a quantum critical point

_{3}

Quantum Criticality in Heavy Electron Compounds

Rh

Crystal Growth, Structure, and Physical Properties of Ln2MGa12 (Ln ) La, Ce; M ) Ni, Cu)

_{4}

Yb

Pb

_3

_{13}

Pt

. Magnetic susceptibility measurements indicate that the Ce moments are highly localized, despite the metallic character of the electrical resistivity. Heat capacity measurements reveal that the cubic crystal electric field lifts the six-fold degeneracy of the Ce

_4

^{3+}

: A New Route to Quantum Criticality

ground state, with the quartet state separated by approximately 60 K from the doublet ground state. The magnetic field dependence of the heat capacity at low temperature indicates a further splitting of the doublet, but no sign of magnetic order was found above 0.35 K.