Mechanical Properties of the Group III Nitrides

A1.1 Common crystal structures of the group III nitrides A1.2 Lattice parameters of the group III nitrides A1.3 Mechanical properties of the group III nitrides A1.4 Thermal properties of the group III nitrides... 

In this Datareview, we have reviewed the mechanical properties of the group III nitrides. From this point of view, they form a very homogeneous family of compounds, with large elastic moduli, both compressional and shear, and bulk moduli of the same order of magnitude as that of diamond. 

The mechanical properties of materials involve various concepts such as hardness, shear and bulk modulus. The group III nitrides are now mostly used as fihns or layers grown by metal organic vapour phase epitaxy (MOVPE) or molecular beam epitaxy (MBE) on sapphire, GaAs or SiC. The lattice parameters of the substrate do not generally match those of the deposited layer, and therefore, stresses appear at the interface and in the layer and modify its physical properties. Hence, it is necessary to have a good knowledge of these properties. 

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