The maximum sustainable amplitude, so‐called wave breaking limit, of a nonlinear plasma wave in arbitrary mass ratio warm plasmas is obtained in the non‐relativistic regime. Using the method of Sagdeev potential, a general wave breaking formula is derived by taking into account the dynamics of both the species having finite temperature. It is found that the maximum amplitude of the plasma wave decreases monotonically with the increase in temperature β−$$ {\beta}_{-} $$ of the negative species (temperature β+$$ {\beta}_{+} $$ of the positive species) and increases (decreases) with increase in mass ratio μ=m−false/m+$$ \mu ={m}_{-}/{m}_{+} $$ provided β−>βcr$$ {\beta}_{-}>{\beta}_{cr} $$ ()β−<βcr$$ \left({\beta}_{-}<{\beta}_{cr}\right) $$, where βcr=1−1−β+1/2/μ2$$ {\beta}_{cr}={\left[1-\left(1-{\beta}_{+}^{1/2}\right)/\sqrt{\mu}\right]}^2 $$.

The effect of electron temperature on the space–time evolution of nonlinear plasma oscillations in an inhomogeneous plasma is studied using a one-dimensional particle-in-cell code. It is observed that, for an inhomogeneous plasma, there exists a critical value of electron temperature beyond which the wave does not break. These simulation results, which are in conformity with the purely theoretical arguments presented by Trines [Phys. Rev. E 79, 056406 (2009)], represent the first numerical elucidation of the effect of plasma pressure on wave breaking amplitude. The results presented are of relevance to experiments where moderate to large amplitude plasma waves are excited, e.g., laser–plasma interaction experiments.

The maximum sustainable amplitude, so-called wave breaking limit, of a nonlinear plasma wave in arbitrary mass ratio warm plasmas is obtained in the non-relativistic regime. Using the method of Sagdeev potential a general wave breaking formula is derived by taking into account the dynamics of both the species having finite temperature. It is found, that the maximum amplitude of the plasma wave decreases monotonically with the increase in temperature and mildly increases with increase in mass ratio.