Anisotropic electrical conductivity,phase transition and thermal hysteresis of a charge-transfer salt dibutylammonium bis-7,7,8,8-tetracyanoquinodimethane DBA(TCNQ)₂

This paper reports that a charge-transfer salt dibutylammonium bis-7,7,8,8-tetracyanoquinodimethane DBA (TCNQ)₂ has been prepared. The temperature dependences of the DC electrical conductivity of the DBA (TCNQ)₂ single crystal measured along the crystallographic a, b, and c axes are reported. The crystal shows semiconducting behaviour and the room-temperature conductivities are highly anisotropic (\sigma_a=3.63\times10^-4 S/cm, \sigma_b=2.84\times10^-6S/cm, and \sigma_c=1.82\times10^-5S/cm). Particularly, a sharp semiconductor to semiconductor transition has been observed around 270 K on the resistivity curves measured under cooling and heating. In addition, thermal hysteresis phenomena on conductivity and differential scanning calorimetry curves are also reported.