Discovery of FeBi₂

Abstract

Recent advances in high-pressure techniques offer chemists access to vast regions of uncharted synthetic phase space, expanding our experimental reach to pressures comparable to the core of the Earth. These newfound capabilities enable us to revisit simple binary systems in search of compounds that for decades have remained elusive. The most tantalizing of these targets are systems in which the two elements in question do not interact even as molten liquids—so-called immiscible systems. As a prominent example, immiscibility between iron and bismuth is so severe that no material containing Fe–Bi bonds is known to exist. The elusiveness of Fe–Bi bonds has a myriad of consequences; crucially, it precludes completing the iron pnictide superconductor series. Herein we report the first iron–bismuth binary compound, FeBi2, featuring the first Fe–Bi bond in the solid state. We employed geologically relevant pressures, similar to the core of Mars, to access FeBi2, which we synthesized at 30 GPa and 1500 K. The compound crystallizes in the Al2Cu structure type (space group I4/mcm) with a = 6.3121(3) Å and c = 5.4211(4) Å. The new binary intermetallic phase persists from its formation pressure of 30 GPa down to 3 GPa. The existence of this phase at low pressures suggests that it might be quenchable to ambient pressure at low temperatures. These results offer a pathway toward the realization of new exotic materials.

Weak Interactions under Pressure: hp‐CuBi and Its Analogues

“…[8,9] In this context, intermetallic compounds of 3d transition metals with bismuth are especially in the focus of interest as they exhibit interesting properties such as superconductivity [8,9] or pronounced spin-orbit splitting. [14] Herein, we report on hp-CuBi, which was manufactured under quasi-hydrostatic conditions at P = 5GPa and T = 720 K, and discuss the electronic and bonding properties of binary copper-bismuth compounds in comparison with selected bismuth-rich phases of transition metals. [11,12] Remarkably,f irst reports on compound formation in the copper-bismuth system date back more than fifty years, [13] but the first binary compound Cu 11 Bi 7 was obtained by highpressure synthesis and structurally characterized only recently.…”

“…[11,12] Remarkably,f irst reports on compound formation in the copper-bismuth system date back more than fifty years, [13] but the first binary compound Cu 11 Bi 7 was obtained by highpressure synthesis and structurally characterized only recently. [14] Herein, we report on hp-CuBi, which was manufactured under quasi-hydrostatic conditions at P = 5GPa and T = 720 K, and discuss the electronic and bonding properties of binary copper-bismuth compounds in comparison with selected bismuth-rich phases of transition metals.…”

Discovery of Cu3Pb

“…Upon removal of pressure, the inherent kinetic stability of the newly created phase can in some cases enable the recovery of the metastable material . Indeed, high‐ PT synthesis has led to the discovery of new metastable materials in numerous binary systems lacking thermodynamically stable binary compounds, such as Fe‐Bi, Cu‐Bi, Co‐Bi …”

Schwache Wechselwirkungen unter Druck: hp‐CuBi und seine Analoga

“…B. Lit. [14] Hier berichten wir über hp-CuBi, das bei quasi-hydrostatischen Bedingungen von P = 5GPa und T = 720 Kh ergestellt wurde, und diskutieren elektronische Eigenschaften sowie die chemische Bindung in binären Kupfer-Bismut-Verbindungen im Vergleich zu ausgewählten Bismut-reichen Phasen von Übergangsmetallen. [10] Im Unterschied zu den Systemen Bi-Co und Bi-Femit ausgedehnten Mischungslücken ist das System Kupfer-Bismut eutektisch.…”

“…[11,12] Bemerkenswerterweise liegen erste Berichte über eine Verbindungsbildung im System Kupfer-Bismut mehr als fünfzig Jahre zurück, [13] aber erst kürzlich konnte die erste binäre Verbindung Cu 11 Bi 7 bei einer Hochdrucksynthese er-halten und strukturell charakterisiert werden. [14] Hier berichten wir über hp-CuBi, das bei quasi-hydrostatischen Bedingungen von P = 5GPa und T = 720 Kh ergestellt wurde, und diskutieren elektronische Eigenschaften sowie die chemische Bindung in binären Kupfer-Bismut-Verbindungen im Vergleich zu ausgewählten Bismut-reichen Phasen von Übergangsmetallen.…”