For 10 points, identify these materials, which exhibit waves that, like a device for determining electron density and temperature in these, are named for Langmuir, which are created when a gas is ionized, the so-called fourth state of matter.
The reciprocal of a length important to these materials, symbolized kappa, appears in the electrostatic potential for a colloid given by the DLVO model. That length characterizes the extent of charge screening that occurs in these materials and is named for Debye. Waves that occur in these materials exhibit a loss of amplitude called Landau damping.  For 10 points, identify these materials, which exhibit waves that, like a device for determining electron density and temperature in these, are named for Langmuir, which are created when a gas is ionized, the so-called fourth state of matter.
The reciprocal of a length important to these materials, symbolized kappa, appears in the electrostatic potential for a colloid given by the DLVO model.
{plasma}s