Universal Phase Transitions of AlB₂-Type Transition-Metal Diborides

Abstract

High-pressure phase transitions of AlB 2 -type transition-metal diborides (TMB 2 ; TM = Zr, Sc, Ti, Nb, and Y) were systematically investigated using first-principles calculations. Upon subjecting to pressure, these TMB 2 compounds underwent universal phase transitions from an AlB 2 -type to a new high-pressure phase tP6 structure. The analysis of the atomistic mechanism suggests that the tP6 phases result from atomic layer folds of the AlB 2 -type parent phases under pressure. Stability studies indicate that the tP6-structured ZrB 2 , ScB 2 , and NbB 2 are stable and may be observed under high pressure and the tP6-structured TiB 2 phase may be recovered at ambient pressure.

Review and Perspectives of Electrochemical Energy Conversion and Storage in Metal Diborides and XBenes

“…Adjusting the temperature allows for the selection of specific phases that are more favorable to electrochemical reactions. This control over phase formation helps optimize the active local electronic structures within the metal diborides. , Similarly, by adjusting the ratio of metal and boron composition, various stoichiometries can be achieved, enabling the tailoring of electronic properties . This optimization of the electronic structure significantly enhances the material’s ability to facilitate fast charge transfer and ion transport for electrochemical reactions .…”

“…Phase engineering of metal diborides can also be achieved by changing reaction temperature or varying the compositional ratio of M/B, optimizing active local electronic structures and hence promoting electrochemical reaction kinetics. , By altering the reaction temperature during the synthesis of metal diborides, we can obtain different crystalline phases. Different phases may have varying electronic structures and properties, affecting their electrochemical behavior .…”

Epigenetics in Esophageal Cancer: From Mechanisms to Therapeutics

“…The authors also showed that miR‐508 overexpression increased the metastasis of ESCC cells both in vitro and in vivo. [ 45 ] Another study revealed that immune checkpoint inhibition could affect the progression of EAC. Major histocompatibility complex class 1 (MHC‐I) proteins are encoded by HLA‐A, HLA‐B, and HLA‐C.…”

Electronic and elastic correlations in AlB2-type two-dimensional hexagonal MBenes

“…Transition metal diborides (TMB 2 ) crystallizes in the hexagonal AlB 2 -type layered structure (P6/mmm space group) having planar graphite-like hexagonally networked boron layer coexisting alternately with closely packed transition metal (TM) layers with TM sitting at center of hexagonal B-ring. AlB 2 -type structured diborides have been investigated experimentally and theoretically for their diverse novel properties ranging from electronic, elastic, thermal to superconductive nature and high pressure studies [3][4][5][6]. Dirac nodal-net semimetal state has also been realized in AlB 2 -type TiB 2 and ZrB 2 with the existence of several topological novel states protected by the spatial-inversion and time-reversal symmetry [7].…”