Anisotropy of Static Electric Permittivity and Conductivity in Some Nematics and Smectics A

摘要: Abstract Anisotropy of static electric permittivity and conductivity was measured for three groups liquid crystals: (I) p-n-alkyl-p'-cyanobiphenyls (CnH2n+1-φ-φ-CN, n = 5,6,7,8), (II) p-p'-dialkylazoxybenzenes (CnH2n+1-φ-N(O) N-φ-CnH2n+1, 5,6,7,8) (III) p-alkyloxyphenyl-p'-alkoxybenzoates (CnH2n+1-O-φ-COO-φ-O-CmH2m+1, 8, m 5; 7; 10, 11, 5). The nematic-smectic A phase transition compounds the I II group manifests itself as a change anisotropy sign due to strong variation parallel component σ∥ only; III both components considerably.