Spin-manipulated doping with magnetic (Ni) and non-magnetic (Mg) dopants constitutes the experimental attempts to obtain a singlet ground state system from the linear chain Heisenberg antiferromagnetic Cu-based d9 spin-1/2 trimer compound Ca3Cu3(PO4)4 with doublet ground state. The present study is a first-principles based investigation of the effects of such doping on the spin-exchange mechanism and electronic structure of the parent compound. Site-selective doping with zero-spin dopants like Mg is proved to be more efficient than an integral spin dopant Ni in obtaining a spin-gap system with singlet ground state, as also observed in the experimental studies. Doping induced dimerized state is found to be the lowest in ground-state energy. Calculated spin exchange values along various possible paths resemble nicely with earlier experimental results.
@article{arxiv.1208.6459,
title = {Doping-induced spin-manipulation in complex trimer system Ca$_{3}$Cu$_{3}$(PO$_{4}$)$_{4}$: A First Principles Study},
author = {Debjani Karmakar and Alexander Yaresko},
journal= {arXiv preprint arXiv:1208.6459},
year = {2015}
}