1、1/30/2023Crystal structure of solids1/30/2023AgendauReviewuSpace latticeuLattice parametersuUnit cellu7 crystal structuresu14 Bravais lattices1/30/2023ReviewuQuick review of previous classnAtomic structurenAtomic bondsnStructure of solidsSOLIDStrong bondingLong range order1/30/2023Space latticeu3D r
2、egular arrangement of points in spaceuHow can the atomic arrangement in solids be mathematically described?uIn two dimensionsXYXYgababg(a)in a Cartesian system(b)in a general system1/30/20233D Space LatticeXYZabcbga1/30/2023Lattice parametersuTo define any lattice 6 lattice parameters are neededua,b
3、,c,(sides)a,b,g,(angles)uHow many unique space lattices can be derived?Only 7 such lattices can be derivedWhen atoms are placed on the lattice points we get CRYSTAL STRUCTURES1/30/2023Unit celluBasic building block in the generation of a space latticeabcgba1/30/2023This(corner of the cube)point is s
4、hared by eight unit cells.Therefore only one-eighth of the point belongs to each unit cell.1/30/20237 crystal structures1/30/202314 Bravais latticeswTriclinicPwMonoclinicPCwRhombohedralPwOrthorhombicPIFCwTetragonalPIwHexagonalPwCubicPIFP=primitiveI=innenzentric(body centered)F=face centeredC=base centered1/30/2023An example1/30/2023SummaryuSpace latticeuLattice parametersuCrystal structuresuBravais lattices1/30/2023PreviewuCubic systemuSimple cubic(SC)uBody centered cubic(BCC)uFace centered cubic(FCC)uMiller indicesuHexagonal system谢谢你的阅读v知识就是财富v丰富你的人生
