  Understanding electron and ion heating phenomenon in capacitively coupled
radio-frequency plasma discharges is vital for many plasma processing
applications. In this article, using particle-in-cell simulation technique we
investigate the collisionless argon discharge excited by temporally asymmetric
sawtooth-like waveform. In particular, a systematic study of the electric field
nonlinearity and field reversal phenomenon by varying the number of harmonics
and its effect on electron and ion heating is performed. The simulation results
predict higher harmonics generation and multiple field reversal regions
formation with an increasing number of harmonics along with the local charge
separation and significant displacement current outside sheath region. The
field reversal strength is greater during the expanding phase of the sheath
edge in comparison to its collapsing phase causing significant ion cooling. The
observed behavior is associated with the electron fluid compression/rarefaction
and electron inertia during expanding and collapsing phase respectively.
