Injection and migration of protons in single crystals of KHSO₄ Available to Purchase

KHSO₄ single crystals are found to be pure ionic conductors with no electronic contribution towards the electrical conduction. A new dc electrolysis cell is designed to measure the transport number of protons, which is found to be 1 (T_H+?1). The current–voltage characteristics along the c axis are interpreted in terms of a space‐charge‐limiting current. The number of thermally produced carriers n₀ and the number of trap centers n_t in pure KHSO₄ crystal at 35 °C are calculated to be 8.70×10¹³ and 2.70×10¹⁴ cm⁻³, respectively. The effective mobility of protons at 35 °C is found to be 4.07×10⁻⁸ cm² V⁻¹⋅sec⁻¹. On the basis of thermogravimetric studies it is confirmed that a KHSO₄ single crystal undergoes an irreversible phase transition around 170 °C. The dc conductance of KHSO₄ single crystals doped with cobalt II is studied in the temperature range of 25 to 165 °C. A break in the conductivity plot is observed suggesting the presence of extrinsic and intrinsic regions. The activation energies for these regions are 0.49±0.01 and 1.21±0.01 eV, respectively. The values for the activation entropy for these regions are −2.2×10⁻³ and 6.04×10⁻⁴ eV K⁻¹, respectively.