Observation of electrical and magnetic property of CaIrO$_{3}$ and CaRhO$_{3}$ post-perovskite by electrical resistivity measurement under high pressure

Since discovery of MgSiO$_{3}$ post-perovskite (PPv) phase, high-pressure polymorph of MgSiO$_{3}$ perovskite (Pv), there are extensive studies regarding physical properties of various PPv materials. It is well known that the crystal structure of high-$T_{c}$ cuprates is based on Pv structure. Material with PPv structure is thus expected to show superconducting behavior with high $T_{c}$. Here we investigated electrical properties of CaIrO$_{3}$ and CaRhO$_{3}$ PPv. These PPv materials are quenchable to ambient condition, and known as a quasi-2D Mott Insulator showing antiferromagnetic transition at low temperature [1,2]. We performed electrical resistivity measurements on the samples under high pressure and low temperature conditions up to 191 GPa, and found that the energy gap of both samples came close to zero with applying pressure. On CaIrO$_{3}$ PPv, we observed an abrupt increase in sample resistivity at low temperature, which is likely to correspond to antiferromagnetic transition in the sample. The N\'{e}el temperature decreased with applying pressure. In the experiments on CaRhO$_{3}$ PPv, we could not observe such resistivity jump likely caused by the magnetic transition.\\[4pt] [1] Yamaura et al., J. AM. CHEM. SOC. 131 2722-2726 (2009)\\[0pt] [2] Ohgushi et al., Physica B 404 3261-3263 (2009)