Discussion On The Conservation Of Order Parameter Relaxation And Point Defects In The Interface Growth System

In this paper we present methods in the study of surfaces and interfaces growth, emphasizing the dynamic Renormalization Group method. We studied the effect of relaxation and point defects in surface growth with a conservation of total height. The influence of these factors on growth exponents is discussed. It deserves regard that we find the existance of a time-random defect results in the decrease of the growth exponent x, which means the surface becomes smoother.In the first part we summarize the basic frame of the study of surface growth. In Chapter 1 we introduce surface and interface growth phenomena and their common scaling behavior. Various Langevin-type eqations describing growing surfaces are presented; In the second chapter methods in the surface and interface growth problem are introduced, presenting the idea of RG method and steps of applying the DRG method to the study of surfaces and interfaces in detail. Also introduced is the scaling approach to growth equations.The second part includes my work. In Chapter 3 relaxation in growth with a conservation law is studied, and reduced roughness of the surface due to the effect of relaxation is found. The last chapter includes discussions of point defects in conservational surface growth. A defect that always exists at some spot on the surface will result in increased surface roughness; While defects that appear randomly with time will, somewhat surprisingly, result in a smoother surface. An attempt to interpret these outcomes is made.