Reufer, Mathias Dietsch, Hervé Gasser, Urs Grobéty, Bernard Hirt, A. M. Malik, Vivek Kumar Schurtenberger, Peter 2011-01-24 Magnetic properties of particles are generally determined from randomly oriented ensembles and the influence of the particle orientation on the magnetic response is neglected. Here, we report on the magnetic characterization of anisotropic spindle- type hematite particles. The easy axis of magnetization is within the basal plane of hematite, which is oriented perpendicular to the spindle axis. Two standard synthesis routes are compared and the effects of silica coating and particle orientation on the magnetic properties are investigated. Depending on the synthesis route we find fundamentally different magnetic behavior compatible with either single domain particles or superparamagnetic sub-units. Furthermore, we show that silica coating reduces the mean blocking temperature to nearly room temperature. The mechanical stress induced by the silica coating appears to reduce the magnetic coupling between the sub-units. application/pdf https://folia.unifr.ch/global/documents/301799 https://folia.unifr.ch/documents/301799/files/reu_mps.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1088/0953-8984/23/6/065102 info:eu-repo/semantics/openAccess License undefined Journal of Physics: Condensed Matter. - 2011, vol. 23, no. 6, p. 065102 info:eu-repo/classification/udc/53 Magnetic properties of silica coated spindle-type hematite particles http://purl.org/coar/resource_type/c_6501