Compensated Half-metallicity in the Trigonally Distorted Perovskite-type NiCrO${}_3$

Abstract

Using first principles calculations, we investigate the electronic and magnetic properties of the trigonally distorted (R-3c) perovskite-derived NiCrO${}_3$. Within the local spin density approximation (LSDA), our calculations show that this system is an exactly compensated half-metal (CHM). The local spin moments of Cr 2.04, and antialigned Ni -1.41 and three oxygens -0.63 (in the units of ${\mu }_B$), indicate high spin S=3/2 Cr${}^{3+}$ and S=3/2 (NiO${}_3$)${}^{3-}$ units. Considering reasonable values of the on-site Coulomb repulsion U on both Ni and Cr ions with LDA+U approach, this system becomes an insulator (as reported by Chamberland and Cloud) having a narrow gap in the spin-up channel, whereas the other channel has a large gap of ~3 eV. Although inclusion of U seemingly leads to the transition Ni${}^{2+}-->highspinS=3/2Ni$^{3+}$,consistentwiththeexperimentallyobservedeffectivemoment,thezeronetmomentremainsunchangedduetoeitherreductionofoxygenlocalmomentsorenhancementofCrlocalmoment.Compressionofvolumeby10$_3$ and provide another route to search for CHM, which is a property sought by many.

5 pages, 5 embedded figures, (To be published in PRB rapid Commun.)

References in corpus (3)

• Anisotropy and Magnetism in the LSDA+U Method
• Half Semimetallic Antiferromagnetism in the Sr${}_2$CrTO${}_6$ System, T=Os, Ru
• Orbital-ordering driven structural distortion in metallic SrCrO3