Magnetic correlations in La2-xSrxCoO4 studied by neutron scattering: possible evidence for stripe phases

Spin correlations in La2-xSrxCoO4 (0.3 < or = x < or = 0.6) have been studied by neutron scattering. The commensurate antiferromagnetic order of La2CoO4 persists in a very short range up to a Sr content of x = 0.3, whereas small amounts of Sr suppress commensurate antiferromagnetism in cuprates and in nickelates. La2-xSrxCoO4 with x > 0.3 exhibits incommensurate spin ordering with the modulation closely following the amount of doping. These incommensurate phases strongly resemble the stripe phases observed in cuprates and nickelates, but incommensurate magnetic ordering appears only at larger Sr content in the cobaltates due to a reduced charge mobility.

Assessing health-related quality of life in patients with Parkinson's disease in a prospective longitudinal study

OBJECTIVE

To prospectively assess the health-related quality of life (HrQoL) in Parkinson's disease (PD) during 12 months.

METHODS

HrQoL was assessed in 145 PD patients using the PD-specific PDQ-39, PDQL and the generic EQ-5D. In addition, clinical rating-scales were used.

RESULTS

All scales showed a pronounced effect of PD. In comparison to an age-matched population the EQ-5D was considerably affected. In comparison to baseline, however, there was no significant change in the generic scale but a significant change in the sum-score of disease-specific HrQoL-scales.

CONCLUSIONS

Only disease-specific scales were sensitive to change. Further studies are necessary to evaluate the time-dependent change in HrQoL.

Spin state transition in LaCoO3 studied using soft x-ray absorption spectroscopy and magnetic circular dichroism

Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-L(2,3) edge, we reveal that the spin state transition in LaCoO3 can be well described by a low-spin ground state and a triply degenerate high-spin first excited state. From the temperature dependence of the spectral line shapes, we find that LaCoO3 at finite temperatures is an inhomogeneous mixed-spin state system. It is crucial that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low- or intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance, and inelastic neutron data.