ISSN:
1572-8854
Schlagwort(e):
Perovskite
;
antiferrodistortive
;
EPR
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Geologie und Paläontologie
,
Physik
Notizen:
Abstract The title compound is a member of the (RNH3)2CuCl4 layer perovskite family, space group C2/c, witha=21.624(5),b=7.511(1),c=7.431(2)Å, β=89.56(2)° andV=1206.9(4)Å3 withZ=4. In the antiferrodistortive structure, the Cu(II) ion assumes an elongated octahedral coordination (unique Cu−Cl distances=2.274(2), 2.288(2), and 3.010(2)Å). The octahedra share corners with four neighbors to form a two-dimensional network. The −NH3 moieties hydrogen bond to the layers, so that the −C2H5OH moieties form sheathes about each metal halide layer. A twofold disorder of the −C2H5OH groups is observed. The EPR spectrum is investigated to help understand the magnetic properties of the systems. Theg-values are consistent with strong intralayer exchange coupling. The EPR linewidths show evidence of spin diffusion effects at liquid nitrogen temperature. However, at room temperature, the spin anisotropies lead to broadening of the EPR lines through a phonon modulation mechanism.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01667021
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