摘要:

Disorder and atomic diffusion are closely connected and these phenomena are the subject of investigations with numerous methods in our laboratory. We will report experiments on diffuse neutron scattering caused by the disorder in a strongly non-stoichiometric iron oxide, which leads to the formation of defect clusters and is related to diffusion and ion conductivity. Secondly, we will present results on quasielastic scattering for a water-doped perovskite with hydrogen atoms randomly bound at OH-ions. This material exhibits the interesting effect of proton conduction. The experiments were carried out on the spectrometers for diffuse scattering (DNS) and for peV-spectroscopy by backscattering (BSS1), both in the FRJ-2 guide laboratory ELLA.

ISSN:1044-8632    

DOI:10.1080/10448639708231961

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The order parameter in binary homopolymer blends or diblock copolymers describes the deviations of the local composition of both components from the mean value. The Fourier transform of the fluctuation spectrum yields the structure factor S(Q), where Q is the wave number of the fluctuations or the momentum transfer in scattering. S(Q→O) is the susceptibility related to the second derivative of the Gibbs potential of mixing with respect to the composition, t32AG/t32z [1–3]. Binary polymer blends normally reveal a miscibility gap that separates the homogeneous one-phase from the two-phase region where precipitation appears. Approaching the critical temperature Tc, the strength and range of thermal fluctuations of the order parameter increase and diverge if Tcis approached.

ISSN:1044-8632    

DOI:10.1080/10448639708231962

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:1044-8632    

DOI:10.1080/10448639708231964

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor