PHYSICAL AND BIOPHYSICAL CHEMISTRY DIVISION
Practical guide to measurement and interpretation of magnetic properties (IUPAC Technical Report)
S. Hatscher1, H. Schilder2, H. Lueken3,*, and W. Urland1,*
1Institut für Anorganische Chemie, Universität Hannover, Callinstrasse 9, 30167 Hannover, Germany; 2Fachbereich Chemieingenieurwesen der Fachhochschule Aachen, Kalverbenden 6, 52066 Aachen, Germany; 3Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Professor-Pirlet-Strasse 1, 52074 Aachen, Germany
Abstract: Rules are pointed out to protect the magnetochemist from pitfalls in both measurement and interpretation of magnetic data. Carefully chosen magnetic field strengths during magnetic susceptibility measurements guarantee the recording of genuine data. With the help of examples, the effect of too strong applied fields is demonstrated producing magnetic saturation and, for example, quenching of weak ferro- or antiferromagnetic spin–spin couplings. In consequence, the data run the risk of being misinterpreted unless model susceptibility equations are applied that take the field dependence of χm into consideration. Recommendations are given for the presentation of experimental and theoretical data. The limited applicability of the most overworked formula in paramagnetism, the Curie–Weiss law χm = C/(T–θ), is clearly presented (magnetically condensed systems, pure spin magnetism). While rough and ready susceptibility formulae are applicable to specific 3d and 4f systems, the complex situation for the remaining d and f centers, including actinides, demands computer programs which consider simultaneously interelectronic repulsion, ligand field potential, spin-orbit coupling, interatomic exchange interactions, and applied magnetic field.
Keywords: magnetic properties; magnetochemistry; SQUID magnetometers; Curie-Weiss law; paramagnetism; Division I.
* Corresponding author.
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