title: Hysteresis losses and specific absorption rate measurements in magnetic nanoparticles for hyperthermia applications.
abstract: Magnetic hysteresis loops areas and hyperthermia on magnetic nanoparticles have been studied with the aim of providing reliable and reproducible methods of measuring the specific absorption rate (SAR).
  
  
  
  The SAR of Fe3O4nanoparticles with two different mean sizes, and Ni1-xZnxFe2O4ferrites with 0 ≤ x ≤ 0.8 has been measured with three approaches: static hysteresis loops areas, dynamic hysteresis loops areas and hyperthermia of a water solution. For dynamic loops and thermometric measurements, specific experimental setups have been developed, that operate at comparable frequencies (≈ 69kHz and ≈ 100kHz respectively) and rf magnetic field peak values (up to 100mT). The hyperthermia setup has been fully modelled to provide a direct measurement of the SAR of the magnetic nanoparticles by taking into account the heat exchange with the surrounding environment in non-adiabatic conditions and the parasitic heating of the water due to ionic currents.
  
  
  
  Dynamic hysteresis loops are shown to provide an accurate determination of the SAR except for superparamagnetic samples, where the boundary with a blocked regime could be crossed in dynamic conditions. Static hysteresis loops consistently underestimate the specific absorption rate but can be used to select the most promising samples.
  
  
  
  A means of reliably measure SAR of magnetic nanoparticles by different approaches for hyperthermia applications is presented and its validity discussed by comparing different methods.
  
  
  
  This work fits within the general subject of metrological traceability in medicine with a specific focus on magnetic hyperthermia. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy. Electronic address: m.coisson@inrim.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Coïsson
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Barrera
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Celegato
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Martino
authors.affiliation: School of Physics, Devi Ahilya University, Indore, India.
authors.forename: Shashank N
authors.initials: SN
authors.lastname: Kane
authors.affiliation: School of Physics, Devi Ahilya University, Indore, India.
authors.forename: Saroj
authors.initials: S
authors.lastname: Raghuvanshi
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Vinai
authors.affiliation: INRIM, strada delle Cacce 91, Torino TO 10135, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Tiberto
mesh_terms: D065966:Absorption, Physicochemical; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006979:Hyperthermia, Induced / Q000379:methods*; D008280:Magnetics / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D050997:Nanomedicine / Q000379:methods*; D010316:Particle Size; D013329:Structure-Activity Relationship; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D058185:Magnetite Nanoparticles; D052203:Ferrosoferric Oxide
keywords: Hysteresis losses; Magnetic hyperthermia; Magnetic nanoparticles; Specific absorption rate