Spin singlet formation in MgTi$_2$O$_4$: evidence of a helical dimerization pattern

(2003)

Authors:

M Schmidt, W Ratcliff, PG Radaelli, K Refson, NM Harrison, SW Cheong

Spin singlet formation in MgTi$_2$O$_4$: evidence of a helical dimerization pattern

ArXiv cond-mat/0308101 (2003)

Authors:

M Schmidt, W Ratcliff II, PG Radaelli, K Refson, NM Harrison, SW Cheong

Abstract:

The transition metal spinel MgTi$_2$O$_4$ undergoes a metal-insulator transition on cooling below $T_{M-I} = 260$ K. A sharp reduction of the magnetic susceptibility below $T_{M-I}$ suggests the onset of a magnetic singlet state. Using high-resolution synchrotron and neutron powder diffraction, we have solved the low-temperature crystal structure of MgTi$_2$O$_4$, which is found to contain dimers with short Ti-Ti distances (the locations of the spin singlets) alternating with long bonds to form helices. Band structure calculations based on hybrid exchange density functional theory show that, at low temperatures, MgTi$_2$O$_4$ is an orbitally ordered band insulator.

High Performances Corrugated Feed Horns for Space Applications at Millimetre Wavelengths

(2003)

Authors:

F Villa, M Sandri, N Mandolesi, R Nesti, M Bersanelli, A Simonetto, C Sozzi, O D'Arcangelo, V Muzzini, A Mennella, P Guzzi, P Radaelli, R Fusi, E Alippi

Erratum: Structural transformation induced by magnetic field and "colossal-like" magnetoresistance response above 313 K in MnAs (Phys. Rev. Lett. (2003) 90 (097203))

Physical Review Letters 90:18 (2003)

Authors:

J Mira, F Rivadulla, J Rivas, A Fondado, T Guidi, R Caciuffo, F Carsughi, PG Radaelli, JB Goodenough

Temperature-induced barium de-trapping from a double-well potential in Ba6Ge25

(2003)

Authors:

M Schmidt, PG Radaelli, MJ Gutmann, SJL Billinge, N Hur, SW Cheong