Nonstandard electroconvection in a bent-core oxadiazole material

TY - JOUR

T1 - Nonstandard electroconvection in a bent-core oxadiazole material

AU - Kaur, Sarabjot

AU - Belaissaoui, Abdel

AU - Goodby, John William

AU - Gortz, Verena

AU - Gleeson, Helen F.

PY - 2011/4/8

Y1 - 2011/4/8

N2 - Electroconvection (EC) phenomena have been investigated in the nematic phase of a bent-core oxadiazole material with negative dielectric anisotropy and a frequency dependent conductivity anisotropy. The formation of longitudinal roll (LR) patterns is one of the predominant features observed in the complete frequency and voltage range studied. At voltages much above the LR threshold, various complex patterns such as the "crisscrossed" pattern, bimodal varicose, and turbulence are observed. Unusually, the nonstandard EC (ns-EC) instability in this material, is observed in a regime in which we measure the dielectric and conductivity anisotropies to be negative and positive respectively. A further significant observation is that the EC displays distinct features in the high and low temperature regimes of the nematic phase, supporting an earlier report that EC patterns could distinguish between regions that have been reported as uniaxial and biaxial nematic phases.

AB - Electroconvection (EC) phenomena have been investigated in the nematic phase of a bent-core oxadiazole material with negative dielectric anisotropy and a frequency dependent conductivity anisotropy. The formation of longitudinal roll (LR) patterns is one of the predominant features observed in the complete frequency and voltage range studied. At voltages much above the LR threshold, various complex patterns such as the "crisscrossed" pattern, bimodal varicose, and turbulence are observed. Unusually, the nonstandard EC (ns-EC) instability in this material, is observed in a regime in which we measure the dielectric and conductivity anisotropies to be negative and positive respectively. A further significant observation is that the EC displays distinct features in the high and low temperature regimes of the nematic phase, supporting an earlier report that EC patterns could distinguish between regions that have been reported as uniaxial and biaxial nematic phases.

UR - http://www.scopus.com/inward/record.url?scp=79961042023&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.83.041704

DO - 10.1103/PhysRevE.83.041704

M3 - Article

SN - 1539-3755

VL - 83

JO - Physical Review E

JF - Physical Review E

IS - 4

M1 - 041704

ER -