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相关论文: Unusual superparamagnetic behavior of Co3O4 nanopa…

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We show that antiferromagnetic susceptibility in ferritin increases with temperature between 4.2 K and 180 K (i. e. below the N\'{e}el temperature) when taken as the derivative of the magnetization at high fields ($30\times10^4$ Oe). This…

强关联电子 · 物理学 2009-11-13 N. J. O. Silva , A. Millan , F. Palacio , E. Kampert , U. Zeitler , H. Rakoto , V. S. Amaral

The resistivity in the ferromagnetic state of flux-grown La_{2/3}(Pb,Ca)_{1/3}MnO_3 single crystals, measured in magnetic fields up to 7 T, reveals a strong quadratic temperature dependence at and above 50 K. At lower temperatures, this…

强关联电子 · 物理学 2009-10-30 M. Jaime , P. Lin , M. B Salamon , P. Han

Magnetization and Mossbauer studies have been performed on the polymer coated magnetite nanoparticles with particle size from 5.1 to 14.7 nm. The maximum in the temperature dependence of magnetization (TM) is found to be inconsistent with…

材料科学 · 物理学 2009-11-11 M. Thakur , K. De , S. Giri , S. Si , A. Kotal , T. K. Mandal

Pronounced anisotropy of magnetic properties and complex magnetic order of a new oxi-halide compound Co7(TeO3)4Br6 has been investigated by powder and single crystal neutron diffraction, magnetization and ac susceptibility techniques.…

材料科学 · 物理学 2013-05-29 M. Prester , I. Zivkovic , O. Zaharko , D. Pajic , P. Tregenna-Piggott , H. Berger

The magnetic properties and the effects of interparticle interaction on it have been studied in nanoparticles of half doped Pr$_{0.5}$Sr$_{0.5}$MnO$_{3}$. Three samples consisting of nanoparticles of different average particle sizes are…

强关联电子 · 物理学 2015-05-19 A. K. Pramanik , A. Banerjee

We report the structural and magnetic properties of ZnO single crystals implanted at 623 K with up to 10 at. % of Ni. As revealed by X-ray diffraction, crystalline fcc-Ni nanoparticles were formed inside ZnO. The magnetic behavior…

材料科学 · 物理学 2007-05-23 Shengqiang Zhou , K. Potzger , Gufei Zhang , F. Eichhorn , W. Skorupa , M. Helm , J. Fassbender

We show that nanostructure and resistivity of Pr0.5Ca0.5Mn0.98Cr0.02O3 are sensitive to whether the sample is zero-field-cooled (ZFC) of field-cooled (FC) either in the 'self magnetic field (H = 2 T)' of the electron microscope or under the…

强关联电子 · 物理学 2009-10-31 M. Hervieu , R. Mahendiran , A. Maignan , C. Martin , B. Raveau

Based on the high-temperature organometallic route (Sun et al. Science 287, 1989 (2000)), we have synthesized powders containing CoPt_3 single crystals with mean diameters of 3.3(2) nm and 6.0(2) nm and small log-normal widths…

材料科学 · 物理学 2009-11-07 F. Wiekhorst , E. Shevchenko , H. Weller , J. Kötzler

We report muon-spin rotation, heat capacity, magnetization, and ac magnetic susceptibility measurements of the layered spin-1/2 antiferromagnet NaNiO2. These show the onset of long-range magnetic order below T_N = 19.5K. Rapid muon…

强关联电子 · 物理学 2010-07-08 P. J. Baker , T. Lancaster , S. J. Blundell , M. L. Brooks , W. Hayes , D. Prabhakaran , F. L. Pratt

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…

材料科学 · 物理学 2009-11-10 Anis Biswas , I. Das , Chandan Majumdar

Spinel Fe3O4 nanoparticles have been produced through ball milling in methyl-alcohol (CH3OH), aiming to obtain samples with similar average particle sizes <d> and different interparticle interactions. Three samples having Fe3O4/CH3(OH) mass…

材料科学 · 物理学 2011-03-24 Gerardo F. Goya

We present measurements of the temperature and field dependencies of the magnetization M(T,H) of Nd(O0.89F0.11)FeAs at fields up to 33T, which show that superconductivity with the critical temperature Tc ~ 51K cannot coexist with…

超导电性 · 物理学 2015-05-13 C. Tarantini , A. Gurevich , D. C. Larbalestier , Z. A. Ren , X. L. Dong , W. Lu , Z. X. Zhao

We report the crystal structure and magnetic properties of Zn1-xCoxO nanoparticles synthesized by heating metal acetates in organic solvent. The nanoparticles were crystallized in wurtzite ZnO structure after annealing in air and in a…

材料科学 · 物理学 2007-05-23 M. Naeem , S. K. Hasanain , M. Kobayashi , Y. Ishida , A. Fujimori , Scott Buzby , S. Ismat Shah

Magnetic dc susceptibility between 1.5 and 800 K, ac susceptibility and magnetization, thermodynamic properties, temperature dependence of radio and audio-wave dielectric constants and conductivity, contact-free dielectric constants at…

We report the results of low-temperature measurements of the specific heat Cp(T), ac susceptibility chi(T) and 23Na nuclear magnetic resonance NMR of Na2V3O7. At liquid He temperatures Cp(T)/T exhibits broad field-dependent maxima, which…

强关联电子 · 物理学 2009-11-11 J. L. Gavilano , E. Felder , D. Rau , H. R. Ott , P. Millet , F. Mila , T. Cichorek , A. C. Mota

The magnetism of nanoparticles and thin films of wide-bandgap oxides that include no magnetic cations is an unsolved puzzle. Progress has been hampered both by the irreproducibility of much of the experimental data, and the lack of any…

介观与纳米尺度物理 · 物理学 2016-01-20 J. M. D. Coey , Karl Ackland , M. Venkatesan , S. Sen

We present the low temperature magnetic properties in Ni1.5Fe1.5O4 ferrite as the function of pH at which the material was prepared by chemical route and post annealing temperature. The material is a ferri or ferromagnet, but showed…

材料科学 · 物理学 2018-05-09 R. N. Bhowmik , K. S. Aneeshkumar

We carried out detailed studies of the magnetic structure, magnetoelastic coupling, and thermal properties of EuCrO$_3$ nano-powders from room temperature to liquid helium temperature. Our neutron powder diffraction and X-ray powder…

强关联电子 · 物理学 2016-04-07 M. Taheri , F. S. Razavi , Z. Yamani , R. Flacau , P. G. Reuvekamp , A. Schulz , R. K. Kremer

The existence of semiconductors exhibiting long-range ferromagnetic ordering at room temperature still is controversial. One particularly important issue is the presence of secondary magnetic phases such as clusters, segregations, etc...…

In this paper, a correlation between structural and magnetic properties of Fe implanted ZnO is presented. High fluence Fe^+ implantation into ZnO leads to the formation of superparamagnetic alpha-Fe nanoparticles. High vacuum annealing at…