PHASE BOUNDARIES NEAR CRITICAL END-POINTS .2. GENERAL SPHERICAL-MODELS

We study d-dimensional ferromagnetic spherical models with power-law, J(R) approximately 1/R(d)+sigma (sigma < 2), or short-range (sigma approximately equals 2) interactions and on-site terms of the form Ds2-\U\s4 + Vs6, and establish that the phase diagrams for all d and sigma with sigma < d < 2-sigma, may exhibit critical end points terminating nonclassical critical lines; tricritical points may arise only for 3/2-sigma less-than-or-equal-to d. The phase boundary D-sigma(T,h), where h is the magnetic field, between the noncritical, spectator phase and the ordering and critical phase is shown to exhibit singularities at the end point with amplitudes obeying the universal ratio laws advanced on phenomenological grounds in Part I.