Clarification of the confusion concerning the crystal-field quantities vs. the zero-field splitting quantities in magnetism studies: Part I—Survey of literature dealing with specific compounds

• Published in: Physica. B, Condensed matter Vol. 403; no. 10; pp. 1882 - 1897
• Main Author: Rudowicz, C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2008; Elsevier
• Subjects: AFMR; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Crystal-field (CF); Crystal-field theory and spin hamiltonians; EMR; EPR; ESR; Exact sciences and technology; FMR; General theory and models of magnetic ordering; Magnetic anisotropy; Magnetic properties and materials; Magnetic specific heat; Magnetic susceptibility; Magnetism; Magnetization; Physics; Spin-Hamiltonian (SH); Zero-field splitting (ZFS); Magnetic specific heat; Spin-Hamiltonian (SH); Magnetization; ESR; EPR; FMR; EMR; Zero-field splitting (ZFS); Magnetic susceptibility; AFMR; Magnetic anisotropy; Magnetism; Crystal-field (CF); Zero field splitting; Crystal field; Fine structure; Spin Hamiltonians; Ligand field; Exchange interactions
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2007.10.219

Physically distinct notions: (i)
crystal field (CF) or equivalently
ligand field (LF), (ii)
magnetic or
magneto-crystalline anisotropy (MA) or equivalently
single-ion anisotropy, and (iii)
exchange interactions (EI) or
spin–spin couplings, appear to be confused in magnetism studies with
zero-field splitting (ZFS) or equivalently
fine structure (FS). Confusion
X=
Y consists in incorrect referral to the quantity
Y by the name
X of another well-defined quantity. Survey of magnetism literature indicates numerous cases of confusion of the type: CF=ZFS, MA=ZFS, EI=ZFS. Since muddled terminology is unhealthy for any area of science, each type of confusion must be clarified. In this review, the CF=ZFS confusion in magnetism literature dealing with specific compounds is clarified. To elucidate this confusion, the CF/LF and ZFS/FS quantities are briefly overviewed. The cases of terminology mixing up: the pertinent Hamiltonians, respective parameters, and energy level splittings, are systematically analysed, classified, and clarified. The structural and/or physical consequences of the confusion as well as of the non-standard parameters are also considered. Implications of each type of confusion go beyond the simple semantic issues and concern misinterpretation of data from a wide range of experimental techniques. The incorrect terminology contributes also to misleading keyword classifications of papers in journals and scientific databases.