Structure
YBCO crystallises in a defect perovskite structure consisting of layers. The boundary of each layer is defined by planes of square planar CuO4 units sharing 4 vertices. The planes can some times be slightly puckered. Perpendicular to these CuO2 planes are CuO4 ribbons sharing 2 vertices. The yttrium atoms are found between the CuO2 planes, while the barium atoms are found between the CuO4 ribbons and the CuO2 planes. This structural feature is illustrated in the figure to the right.
Read more about this topic: Yttrium Barium Copper Oxide
Famous quotes containing the word structure:
“A structure becomes architectural, and not sculptural, when its elements no longer have their justification in nature.”
—Guillaume Apollinaire (1880–1918)
“There is no such thing as a language, not if a language is anything like what many philosophers and linguists have supposed. There is therefore no such thing to be learned, mastered, or born with. We must give up the idea of a clearly defined shared structure which language-users acquire and then apply to cases.”
—Donald Davidson (b. 1917)
“What is the most rigorous law of our being? Growth. No smallest atom of our moral, mental, or physical structure can stand still a year. It grows—it must grow; nothing can prevent it.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)