Examples are arbitrarily aligned, optically uniaxial samples, or optically biaxial samples. This is true of either a uniaxial or biaxial material. A magnetic particle with uniaxial anisotropy has one easy axis. The anisotropy of such crystals is called "uniaxial anisotropy". However, rather than applying a uniaxial tensile load, a uniaxial compressive load is applied. In general the anisotropy parameters for cubic ferromagnets are higher than those for uniaxial ferromagnets. This applies to a particle with uniaxial magnetocrystalline anisotropy. For considering the uniaxial anisotropy of the material, Everett functions are expanded by Fourier coefficients. The uniaxial anisotropy is mainly determined by the first two terms. Yield occurs when the largest principal stress exceeds the uniaxial tensile yield strength. In the simplest form, uniaxial birefringence, there is only one special direction in the material. This can be achieved through uniaxial or isostatic processes. Consider a composite material under uniaxial tension formula 7. Yield occurs when the pressure is greater than the uniaxial yield stress. In positive uniaxial crystals, types VII and VIII are more suitable.