We demonstrate the relation $\theta =2\mathrm{}\phi$. Here the exponent $\theta$ is defined as $D\sim N^{\theta }$, where $D$ is the equilibrium lamellar thickness of the diblock copolymer ordered phase and $N$ is the molecular weight. The exponent $\phi$ is defined as $l\sim t^{\phi }$, where $l$ is the pattern size of the spinodally decomposing system (say, a binary alloy) and $t$ is the time.

• Received 27 June 1988

DOI:https://doi.org/10.1103/PhysRevLett.61.1109