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This work focuses on the microstructure, magnetic properties and magnetocaloric effect of CoFe$_2$O$_4$ (CFO) nanoparticles elaborated by sol-gel auto combustion method. The XRD investigation indicates that CFO is crystallized in a cubic…

We determine the magnetic phase diagram for the YBa$_2$Cu$_3$O$_{6+x}$ and La$_{2-x}$Sr$_x$CuO$_4$ systems from various NMR experiments. We discuss the possible interpretation of NMR and neutron scattering experiments in these systems in…

Condensed Matter · Physics 2009-10-28 V. Barzykin , D. Pines

We have studied the magnetic and power absorption properties of three samples of CoFe2O4 nanoparticles with sizes from 5 to 12 nm prepared by thermal decomposition of Fe (acac)3 and Co(acac)2 at high temperatures. The blocking temperatures…

Materials Science · Physics 2011-03-22 T. E. Torres , A. G. Roca , M. P. Morales , A. Ibarra , C. Marquina , M. R. Ibarra , G. F. Goya

In transition metal oxides, quantum confinement arising from a large surface to volume ratio often gives rise to novel physico-chemical properties at nanoscale. Their size dependent properties have potential applications in diverse areas,…

Bulk nanocrystalline materials of small and medium ferromagnetic content were produced using severe plastic deformation by high-pressure torsion at roomtemperature. Giant magnetoresistive behavior was found for as deformed materials, which…

Materials Science · Physics 2020-09-08 Stefan Wurster , Martin Stueckler , Lukas Weissitsch , Timo Mueller , Andrea Bachmaier

Nd_0.5 Ca_0.5 MnO_3 (NCMO) nanoparticles (average diameter ~ 20 and 40 nm) are synthesized by polymeric precursor sol-gel method and characterized by X- ray diffraction, transmission electron microscopy (TEM), selective area electron…

Strongly Correlated Electrons · Physics 2009-11-11 S. S. Rao , S. V. Bhat

We report on electrical resistivity, magnetoresistance (MR) and Hall effect measurements in four non-superconducting BaFe$_{2-x}$TM$_x$As$_2$ (TM = Mn, Cu and Ni) single crystals with small values of the chemical substitution $x$. The spin…

In this work nanometric spinel Co${}_{1-x}$Cu${}_{x}$Fe${}_{2}$O${}_{4}$ powders were obtained by polymeric precursors method at several annealing temperatures between 700 and 1200 ${}^\circ$C. The samples were characterized by means of…

We report magnetic measurements up to 1200 K on multi-walled carbon nanotube mats using Quantum Design vibrating sample magnetometer. Extensive magnetic data consistently show two ferrromagnetic-like transitions at about 1000 K and 1275 K,…

Superconductivity · Physics 2010-03-11 Guo-meng Zhao , Pieder Beeli

We present a thorough $^{77}$Se NMR study of a single crystal of the magnetoelectric compound Cu$_2$OSeO$_3$. The temperature dependence of the local electronic moments extracted from the NMR data is fully consistent with a magnetic phase…

Strongly Correlated Electrons · Physics 2010-09-17 M. Belesi , I. Rousochatzakis , H. C. Wu , H. Berger , I. V. Shvets , F. Mila , J. P. Ansermet

Fine powders of micron- and submicron-sized particles of undoped Cu2O semiconductor, with three different sizes and morphologies have been synthesized by different chemical processes. These samples include nanospheres 200 nm in diameter,…

Materials Science · Physics 2010-05-11 Chinping Chen , Lin He , Lin Lai , Hua Zhang , Jing Lu , Lin Guo , Yadong Li

We have investigated the magnetic behavior of ball-milled fine particles of well-known Kondo lattices, CeAu2Si2, CePd2Si2 and CeAl2, by magnetization and heat-capacity studies in order to understand the magnetic behavior when the particle…

Strongly Correlated Electrons · Physics 2015-06-03 K. Mukherjee , Kartik K. Iyer , E. V. Sampathkumaran

Magnetic nanoparticles (NP) of magnetite (Fe3O4) coated with oleic acid (OA) and dodecanoic acid (DA) were synthesized and investigated through Transmission Electron Microscopy (TEM),magnetization M, and ac magnetic susceptibility…

Mesoscale and Nanoscale Physics · Physics 2010-04-14 V. B. Barbeta , R. F. Jardim , P. K. Kiyohara , F. B. Effenberger , L. M. Rossi

The study of the magnetic properties depending upon mechanical milling of the ferromagnetic polycrystalline TbAl_2 material is reported. The Rietveld analysis of the X-ray diffraction data reveals a decrease of the grain size down to 14 nm…

Disordered Systems and Neural Networks · Physics 2015-06-25 D. P. Rojas , L. Fernandez Barquin , J. Rodriguez Fernandez , J. I. Espeso , J. C. Gomez Sal

Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20 nm in diameter were synthesized by thermal decomposition of an iron organic precursor in an organic medium. Particles were coated with oleic acid. For all samples…

Materials Science · Physics 2011-11-09 P. Guardia , B. Batlle-Brugal , A. G. Roca , Oscar Iglesias , M. P. Morales , C. J. Serna , A. Labarta , X. Batlle

The role of particle size distribution inherently present in magnetic nanoparticles (NPs) is examined in considerable detail in relation to the measured magnetic properties of oleic acid-coated maghemite ({\gamma}-Fe$_2$O$_3$) NPs.…

Materials Science · Physics 2015-10-29 Kelly L. Pisane , Emily C. Despeaux , Mohindar S. Seehra

Transport and magnetic properties have been studied in two sets of sol-gel prepared Pr$_{1/2}$Sr$_{1/2}$MnO$_{3}$ nanoparticles having average particle size of 30 nm and 45 nm. Our measurements suggest that the formation of charge ordered…

Materials Science · Physics 2009-11-10 Anis Biswas , I. Das , Chandan Majumdar

In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe2O4 treated by mechanical milling with different grinding balls. The cobalt ferrite nanoparticles were prepared using a simple hydrothermal method and…

Materials Science · Physics 2013-01-10 A. S. Ponce , E. F. Chagas , R. J. Prado , C. H. M. Fernandes , A. J. Terezo , E. Baggio-Saitovitch

We have investigated the magnetic properties of carbon powders which consist of nanodisks, nanocones, and a small fraction of carbon-black particles. Magnetization measurements were carried out using a superconducting quantum interference…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Jozef Cernak , Geir Helgesen , Jozef Kovac , Arne T. Skjeltorp , Josef Voltr

Copper ferrite nanoparticles have catalytic activity for hydrogen peroxide, which can be used in many fields. This characteristic comes from the physical properties of matters at nanometer scale. Thus, controlling the size and aggregation…

Applied Physics · Physics 2023-10-13 Zihan Huang , Siyi Li , He Ding , Piao Pingyang , Jun Xinhuang