Incorporation of carbon atoms in rare earth boron-rich solids and formation of superstructures

Abstract

The boron-rich solid of YB25 can incorporate certain amounts of carbon atoms. With increase of carbon content, two kinds of superstructures of YB25, which modulate the basic structure in the (001) plane, appeared. The framework of boron icosahedra in the superstructures remains the same as that of YB25 and the structural modulation is just caused by the variation of carbon distribution in the voids of the framework. In addition, one superstructure with a large unit cell is quenchable and transformed into another superstructure by thermal annealing at 1400°C for 80 h.