Monodispersed Transition Metals Induced Ordinary-Pressure Phase Transformation from Graphite to Diamond: A First-Principles Calculation

High pressure and high temperature are normally requiredfor thetransformation of graphite to diamond; thus, finding a method thatallows the transformation to occur under ordinary pressure will beextremely promising for diamond synthesis. Here, it is found thatgraphite spontaneously transforms into diamond without any pressureby adding monodispersed transition metals, and the universal rulesthat will help predict the role of certain elements in the phase transitionwere studied. The results show that the favorable transition metalspossess an atomic radius of 0.136-0.160 nm and an unfilledd-orbital of d(2)s(2)-d(7)s(2), which allow more charge transfer and accumulation at theproper position between the metal and dangling C atoms, leading tostronger metal-C bonds and a lower energy barrier for the transition.This provides a universal method to prepare diamond from graphiteunder ordinary pressure and also provides a way for the synthesisfrom sp(2) to sp(3) bonded materials.

Automated summary

By adding monodispersed transition metals, graphite can spontaneously transform into diamond without any pressure, which provides a promising method for diamond synthesis. The study also establishes universal rules for predicting the role of certain elements in the phase transition.