Structure of solids - islam Flashcards
What are the four main solid types?
Ionic solid, metal, covalent network and molecular solids.
What are solid materials important for?
Fundamental research and technological applications, such as heterogeneous catalysis, batteries, semiconductors and solar cells.
What is body centred cubic structure?
It is neither hcp or ccp and is not as common. It has a lattice site at the centre of the cube with atoms at the corners.
What is the definition of the unit cell?
It is the smallest repeating unit that show the full symmetry of the solid structure which repeat in 3D to give an infinite solid lattice.
What are the features of the cubic crystal system?
a=b=c, alpha=beta=gamma=90 degrees.
What are the features of the tetragonal crystal system?
a=b, alpha=beta=gamma= 90 degrees.
What are the features of the orthorhombic crystal system?
Neither a, b or c are equal, but alpha=beta=gamma= 90 degrees.
What are the features of the monoclinic crystal system?
Neither a, b or c are equal, alpha=gamma=90, but beta is a different angle.
What are the features of the triclinic crystal system?
Neither a, b, c, alpha, beta or gamma are equal.
What are the features of the hexagonal crystal system?
a=b but c is different, alpha=beta=90, but gamma =120.
What are the features of the trigonal/rhombohedral crystal system?
a=b=c, alpha=beta=gamma are NOT equal to 90 degrees.
In terms of radius ratio, what gives the most stable structure?
Maximising contact between cations and anions.
What is the radius ratio equation?
R+/R-
