Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

Abstract

The unusual property of negative thermal expansion is of fundamental interest and may be used to fabricate composites with zero or other controlled thermal expansion values. Here we report that colossal negative thermal expansion (defined as linear expansion <−10−4 K−1 over a temperature range ~100 K) is accessible in perovskite oxides showing charge-transfer transitions. BiNiO3 shows a 2.6% volume reduction under pressure due to a Bi/Ni charge transfer that is shifted to ambient pressure through lanthanum substitution for Bi. Changing proportions of coexisting low- and high-temperature phases leads to smooth volume shrinkage on heating. The crystallographic linear expansion coefficient for Bi0.95La0.05NiO3 is −137×10−6 K−1 and a value of −82×10−6 K−1 is observed between 320 and 380 K from a dilatometric measurement on a ceramic pellet. Colossal negative thermal expansion materials operating at ambient conditions may also be accessible through metal-insulator transitions driven by other phenomena such as ferroelectric orders.

Magnetic and orbital orders coupled to negative thermal expansion in Mott insulators Ca2Ru1−xMxOQi1, Korneta2, Parkin3 et al. 2012Phys. Rev. B362401View full textAdd to dashboardCite

“…The observed lattice anomaly at T N is clearly a magnetovolume effect, which originates from a strong correlation between the lattice expansion and spin frustration [14]. It is noted that the origin of the NTE recently observed in BiNiO 3 is attributed to charge transfer [22].…”

Inverse barocaloric effect in the giant magnetocaloric La–Fe–Si–Co compound

“…Such a volume increase gives rise to a negative thermal expansion (NTE) within a certain temperature range. Materials exhibiting colossal NTE resulting from phase transitions are receiving considerable interest 23 . From thermodynamic arguments, it can be expected that these materials with NTE will also exhibit inverse barocaloric eff ects.…”

Negative thermal expansion properties in tetragonal NbPO5 from the first principles studies

“…However, the nature of the NTE is complicated since it is entangled with some factors like magnetic transitions and Ferro-electricity, changes of the electronic configuration, etc. [35][36][37] Fig. 3, can be classified into two types.…”