Material Parameters and Intrinsic Optical Bistability in Room Temperature Nematics RO-TN-200, -201, -403, E7,m₁, andm₃

New measurements are reported of the elastic constants and refractive indices of the room temperature nematics RO-TN-200, -201, -403 and E7. The new measured material parameters show that the purely optical field induced first-order Freedericksz transition can not be attained by these materials. However, the first-order Freedericksz transition can be enhanced in these nematics by an external magnetic field. We also report two new nematic mixtures for which the purely optical field induced first-order Freedericksz transition can be attained.