Investigation of the structure of barium iridate (BaIrO3) by high-resolution electron microscopy

Four decades of research in solid state chemistry

“…I also studied the electronic structures of oxides by employing X-ray photoelectron spectroscopy (ESCA). HREM investigations included many interesting oxides such as the Aurivillus family of oxides, perovskite polytypes and silicon carbide (Gai et al 1975(Gai et al , 1976Hutchison et al 1976). When I came back from Oxford to IIT Kanpur, it was clear that I required much better characterization and measurement facilities to carry out meaningful research in solid state chemistry.…”

Novel Charge Ordering in the Trimer Iridium Oxide BaIrO3

“…The trimers are connected with each other in a corner-sharing network and construct zig-zag chains along the c axis and corrugated honeycomb lattices in the ab plane. Owing to the low crystal symmetry of C2/m, two trimers are inequivalent in the unit cell, as painted in different colors in the inset of Figure 1b The study of this oxide has a rather long history; Donohue et al first reported the synthesis and structure of this material in the 60s, [3], and later Gai et al [4] studied the poly-types of 5H and 6H. Chamberland [5] extensively studied the relationship of the poly-types to the synthetic routes, and further found a magnetic phase transition near 200 K. The physical and chemical properties of the poly-types have been measured rather recently because of difficulty in the sample synthesis [6,7].…”

Giant nonlinear conduction and thyristor-like negative differential resistance inBaIrO3single crystals

“…The crystal structure of BaIrO 3 is monoclinic (space group C2/m) [18,19], and contains zigzag chains of the Ir 3 O 12 trimer with the face shared IrO 6 octahedra along the c-axis as shown in Fig 1 . Each trimer is linked to form a corner-shared network along the c axis, and a two-dimensional network perpendicular to the c axis as well. The band calculation revealed a fairly dispersive band along the ab plane as well as along the c axis [16].…”