RT Journal Article T1 Colossal heating efficiency via eddy currents in amorphous microwires with nearly zero magnetostriction A1 Morales Casero, Irene A1 Archilla Sanz, Diego A1 Presa Muñoz del Toro, Patricia de la A1 Hernando Grande, Antonio A1 Marín Palacios, María Pilar AB It is well stablished that heating efficiency of magnetic nanoparticles under radiofrequency fields is due to the hysteresis power losses. In the case of microwires (MWs), it is not clear at all since they undergo non-coherent reversal mechanisms that decrease the coercive field and, consequently, the heating efficiency should be much smaller than the nanoparticles. However, colossal heating efficiency has been observed in MWs with values ranging from 1000 to 2800W/g, depending on length and number of microwires, at field as low as H = 36 Oe at f = 625 kHz. It is inferred that this colossal heating is due to the Joule effect originated by the eddy currents induced by the induction field B = M + chi H parallel to longitudinal axis. This effect is observed in MWs with nearly zero magnetostrictive constant as Fe_ (2.25)Co_(72.75)Si_(10)B_(15) of 30 mu m magnetic diameter and 5 mm length, a length for which the inner core domain of the MWs becomes axial. This colossal heating is reached with only 24 W of power supplied making these MWs very promising for inductive heating applications at a very low energy cost. PB Nature Publishing group SN 2045-2322 YR 2020 FD 2020-01-17 LK https://hdl.handle.net/20.500.14352/6247 UL https://hdl.handle.net/20.500.14352/6247 LA eng NO ©2020 Nature Publishing groupThis work was supported by grants from the Spanish Ministry of Science and Innovation RTI2018-095856-B-C21 and Comunidad de Madrid NANOMAGCOST S2018/NMT-4321. The authors also acknowledge the technical support given by Fernando Giacomone financed by Spanish Ministery of Science and Innovation, PTA2015-10497-I. NO Ministerio de Ciencia e Innovación (MICINN) NO Comunidad de Madrid DS Docta Complutense RD 4 may 2024