Increased hole mobility in anti-ThCr₂Si₂-type La₂O₂Bi co-sintered with alkaline earth metal oxides for oxygen intercalation and hole carrier doping

Abstract

Metallic anti-ThCr2Si2-type RE2O2Bi (RE = rare earth) with Bi square nets show superconductivity while insulating La2O2Bi shows high hole mobility, by expanding the c-axis length through oxygen intercalation. In this...

Superconductivity and improved electrical conduction in anti-ThCr2Si2-type RE2O2Sb and RE2O2Bi with pnictogen square net

“…Chemical doping other than oxygen intercalation was also effective in controlling the electrical properties of Y 2 O 2 Bi and La 2 O 2 Bi (Matsumoto et al, 2021;Terakado et al, 2022). For Y 2 O 2 Bi, H substitution for O, F substitution for O, and Li intercalation were reported.…”

“…However, the oxygen intercalation realized metallic La 2 O 2 Bi, originating from the improved hole carrier mobility, which was as high as 83 cm 2 /Vs. Oxygen intercalation was also performed using CaO as an oxidant, further increasing the c-axis length (Matsumoto et al, 2021). As a result, the mobility was enhanced up to 150 cm 2 /Vs (Figures 6A and 6B), which was nearly the highest value among other polycrystalline layered oxypnictides and oxychalcogenides (Figure 6C).…”

“…Oxygen-intercalated La 2 O 2 Bi was prepared by controlling the nominal amount of oxygen in the solid-state reaction (Matsumoto et al, 2020). The oxygen intercalation did not induce superconductivity in semiconducting La 2 O 2 Bi, in contrast to other metallic RE 2 O 2 Bi (Matsumoto et al, 2021). However, the oxygen intercalation realized metallic La 2 O 2 Bi, originating from the improved hole carrier mobility, which was as high as 83 cm 2 /Vs.…”

Multilayer Solid-Phase Epitaxy of La2O2Bi Thin Films toward Higher Electrical Conduction in a Monatomic Bi Square Net Semimetal

“…However, the oxygen nonstoichiometry in La 2 O 2 Bi significantly influenced the electrical conduction. The excess oxygen intercalated La 2 O 2 Bi bulk polycrystal showed metallic conduction, and the polarity of conduction carriers was varied by the excess or deficient oxygen. , In order to clarify intrinsic conduction of La 2 O 2 Bi, a single crystalline specimen has been desired.…”

“…In this study, La 2 O 2 Bi epitaxial thin films were grown for the first time. Nearly stoichiometric La 2 O 2 Bi epitaxial thin films were obtained on MgO substrates, exhibiting zero band gap and improved electrical conduction in comparison with the La 2 O 2 Bi bulk polycrystal. , The small Hall coefficient and temperature-induced career inversion suggest a semimetallic electronic state in La 2 O 2 Bi.…”