2002/08/30 by A. Yakubovskii, A. Trokiner, S. V. Verkhovskiǐ +4 · 20 citations
Chemistry · Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Charge (physics) #Charge ordering #Chemistry #Condensed matter physics #Crystallography #High-pressure geophysics and materials #Magnetic and transport properties of perovskites and related materials #Order (exchange) #Physics #Quantum mechanics #Spectral line #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.67.064414
published in Physical review. B, Condensed matter 67(6) (American Physical Society)
arxiv created 2002/08/30 · openalex publication_date 2003/02/26 · arxiv updated 2009/11/30 · openalex created_date 2019/12/13 · openalex updated_date 2026/08/05
The charge and orbital ordering in Pr0.5Ca0.5MnO3 is studied for the first time by17O NMR. This local probe is sensitive to spin, charge, and orbital correlations. Two transitions exist in this system: the charge and orbital ordering at TCO=225K and the antiferromagnetic (AF) transition at TN=170K. Both are clearly seen in the NMR spectra measured in a magnetic field of 7 T. Above TCO there exists only one NMR line with a large isotropic shift, whose temperature dependence is in accordance with the presence of ferromagnetic (FM) correlations. This line splits into two parts below TCO, which are attributed to different types of oxygen in the charge-/orbital ordered state. The interplay of FM and AF spin correlations of Mn ions in the charge-ordered state of Pr0.5Ca0.5MnO3 is considered in terms of the hole hopping motion that slows down with decreasing temperature. The developing fine structure of the spectra evidences that there still exist charge-disordered regions at TCO>T>TN and that the static (t>10^\ensuremath-6s) orbital order is established only on approaching TN. The charge-exchange (CE) type magnetic correlations develop gradually below TCO, so that at first the AF correlations between checkerboard ab layers appear, and only at lower temperature do CE correlations within the ab planes appear.