The effect of pressure on magnetic properties of LaCoO3 is studied experimentally and theoretically. The pressure dependence of magnetic susceptibility χ of LaCoO3 is obtained by precise measurements of χ as a function of the hydrostatic pressure P up to 2 kbar in the temperature range from 78 K to 300 K. A pronounced magnitude of the pressure effect is found to be negative in sign and strongly temperature dependent. The obtained experimental data are analysed by using a two-level model and DFT+U calculations of the electronic structure of LaCoO3. In particular, the fixed spin moment method was employed to obtain a volume dependence of the total energy difference Δ between the low spin and the intermediate spin states of LaCoO3. Analysis of the obtained experimental χ(P) dependence within the two-level model, as well as our DFT+U calculations, have revealed the anomalous large decrease in the energy difference Δ with increasing of the unit cell volume. This effect, taking into account a thermal expansion, can be responsible for the temperatures dependence of Δ, predicting its vanishing near room temperature.
@article{arxiv.1801.01325,
title = {Pressure effect on magnetic susceptibility of LaCoO$_3$},
author = {A. S. Panfilov and G. E. Grechnev and I. P. Zhuravleva and A. A. Lyogenkaya and V. A. Pashchenko and B. N. Savenko and D. Novoselov and D. Prabhakaran and I. O. Troyanchuk},
journal= {arXiv preprint arXiv:1801.01325},
year = {2018}
}