posted on 2019-05-06, 00:00authored byNaizheng Wang, Xingxing Jiang, Maxim S. Molokeev, Gaomin Song, Shibin Guo, Rongjin Huang, Laifeng Li, Yicheng Wu, Zheshuai Lin
We
report the discovery of the zero thermal expansion (ZTE) effect
in BPO4, a famous deep-ultraviolet (DUV) optical material
with cristobalite-like structure. It is revealed that BPO4 has a linear ZTE coefficient of −0.16(5) MK–1 along the c-axis as temperature increases from
13 to 300 K, which originates from the subtle counterbalance between
the rotation-induced expansion and contraction effects among BO4 and PO4 groups. BPO4 is a unique DUV
cristobalite-like material exhibiting the linear ZTE behavior.