Yankun Yin

Abstract Inspired by noncollinear magnetic dipole order, noncollinear electric dipole order is anticipated to open up rich ferroelectric physics and new opportunities for device applications. However, establishing such order in single crystals remains challenging, as electric polarization is typically locked to crystallographic axes. Here we report noncollinear ferrielectricity in the van der Waals crystal WO2Br2, arising from competition between ferroelectric and antiferroelectric phonon modes.

This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessArticle by Yankun Yin 1,2,†, Jin Yan 1,3,4,†, Chushan Deng 4 and Dapeng Zhang 3,4,* 1 College of Mechanical Engineering, Guangdong Ocean University, Zhanjiang 524088, China 2 CNOOC China Ltd.

Abstract Natural and synthetic diamonds mostly have a cubic lattice, whereas a rare hexagonal structure—known as hexagonal diamond (HD)—has been largely unexplored due to the low purity and minuscule size of most samples obtained. The synthesis of HD remains a challenge and even its existence remains controversial. Here we report the synthesis of well-crystallized, nearly pure HD by heating highly compressed graphite, which is applicable to both bulk and nanosized graphitic precursors.