First-principles study on the negative/zero area compressibility in Ag3BO3 with “wine-rack” architecture

Abstract

Materials with negative/zero area compressibility (NAC or ZAC), which expand or keep constant along two directions under hydrostatic pressure, are very rare but of great scientific and engineering merits. Here, we investigate “wine-rack” architecture, which is the most prevailing for the pressure-expansion effect in materials, and identify that two allotropes (Ag3BO3-I and -II ) of Ag3BO3 have the ZAC and NAC effects, respectively, by the first-principles calculations. Structural analysis discloses that the competition between the contraction effect from the bond length/angle shrinkage and the expansion effect from the angle closing between O-Ag-O bars and the (a , b ) plane dominates the occurrence of ZAC/NAC, and the framework openness governs the competing balance in this system. This work deepens the understanding of “wine-rack” models and enriches the NAC/ZAC family.