Universality in adsorbate ordering on nanotube surfaces

TL;DR

This paper develops a transfer matrix method to study adsorbate ordering on nanotubes, revealing phase transition behaviors consistent with universality principles and the 1D Ising model.

Contribution

A new transfer matrix approach for analyzing adsorbate phase transitions on nanotubes, linking critical behavior to universality and interphase boundary properties.

Findings

Adsorbate ordering exhibits phase transition-like behavior.

Behavior aligns with the universality hypothesis of critical phenomena.

Quantitative critical parameters relate to interphase boundary properties.

Abstract

Numerically efficient transfer matrix technique for studying statistics of coherent adsorbates on small nanotubes has been developed. In the framework of a realistic microscopic model fitted to the data of ab initio calculations taken from literature sources, the ordering of potassium adsorbate on (6,0) single-walled carbon nanotube has been studied. Special attention has been payed to the phase transition-like abrupt changes seen in the adsorption isotherms at low temperature. It has been found that the behavior during the transitions conforms with the universality hypothesis of the theory of critical phenomena and is qualitatively the same as in the one dimensional Ising model. Quantitatively the critical behavior can be fully described by two parameters. Their qualitative connection with the properties of interphase boundaries is suggested but further research is needed to develop a quantitative theory.