Room-temperature ferromagnetism in MgO nanocrystalline powders

Jifan Hu; Zhongli Zhang; Ming Zhao; Hongwei Qin; Minhua Jiang
November 2008
Applied Physics Letters;11/10/2008, Vol. 93 Issue 19, p192503
Academic Journal
MgO nanocrystalline powders prepared by sol-gel method present room-temperature ferromagnetism, whereas MgO bulk exhibits diamagnetism. The vacuum annealing of MgO nanocrystalline powders reduces ferromagnetism. The observed room-temperature ferromagnetism in MgO nanocrystalline powders possibly originates from Mg vacancies at/near the surfaces of nanograins. Mg vacancies can induce local magnetic moments. Large concentrations of Mg vacancies at the surfaces of nanograins possibly establish magnetic percolation.


Related Articles

  • Constitutive description of creep behavior of M-4Al-1Ca alloy. Milička, K.; Dobeš, F. // Strength of Materials;Jan2008, Vol. 40 Issue 1, p28 

    Creep behavior of an advanced magnesium alloy AX41 (4 wt.% Al, 1 wt.% Ca, Mg balanced) was investigated in temperature interval from 343 to 673 K and stresses from 2 to 200 MPa. Compressive creep experiments with stepwise loading were used in order to obtain stress dependence of the creep rate...

  • The Effect of Alkali and Ce(III) Ions on the Response Properties of Benzoxazine Supramolecules Prepared via Molecular Assembly. Kaewvilai, Attaphon; Rujitanapanich, Sawittree; Wattanathana, Worawat; Veranitisagul, Chatchai; Suramitr, Songwut; Koonsaeng, Nattamon; Laobuthee, Apirat // Molecules;Jan2012, Vol. 17 Issue 1, p511 

    A series of benzoxazine monomer supramolecules with different substituted groups on their benzene ring was prepared with a Mannich reaction and characterized by FTIR, 1H-NMR and MS. The obtained products were 3,4-dihydro-3-(2'-hydroxyethylene)-6-methyl-2H-benzoxazine (BM1),...

  • Synthesis and tunable photoluminescence of NaYF4:Eu/Ba nanocrystals. Guofeng Wang; Qing Peng // Journal of Materials Research;Dec2010, Vol. 25 Issue 12, p2422 

    Sub-10 nm monodispersed NaYF4:Eu/Ba nanocrystals were synthesized by a hydrothermal method. Under 396-nm excitation, in addition to the characteristic emissions of Eu3+ ions, an intense emission band originating from the d--f transition of the Eu2+ ions is also observed, indicating that Eu3+ and...

  • A Study of Ferromagnetic Signals in SrTiO3 Nanoparticles. Kovacs, P.; Des Roches, B.; Crandles, D. A. // AIP Conference Proceedings;2014, Vol. 1590, p87 

    It has been suggested that ferromagnetism may be a universal feature of nanoparticles related to particle size. We study this claim for the case of commercially produced SrTiO3 nanoparticles purchased from Alfa-Aesar. Both loosely-packed nanoparticle samples and pellets formed using uniaxial...

  • The High Temperature Ising Model on the Triangular Lattice is a Critical Bernoulli Percolation Model. B�lint, Andr�s; Camia, Federico; Meester, Ronald // Journal of Statistical Physics;Apr2010, Vol. 139 Issue 1, p122 

    We define a new percolation model by generalising the FK representation of the Ising model, and show that on the triangular lattice and at high temperatures, the critical point in the new model corresponds to the Ising model. Since the new model can be viewed as Bernoulli percolation on a random...

  • Sorption of radioiodine from aqueous solutions on layered double magnesium aluminum hydroxides at 300 K. Kulyukhin, S. A.; Krasavina, E. P.; Rumer, I. A.; Mizina, L. V.; Konovalova, N. A. // Radiochemistry;Sep2007, Vol. 49 Issue 5, p499 

    Sorption of 131I− and 131IO from aqueous solutions at 300 K on solid layered double magnesium aluminum hydroxides (Mg-Al-LDH) in the carbonate (Mg-Al-LDH-CO3) and nitrate (Mg-Al-LDH-NO3) forms was studied. The distribution coefficients of 131I− and 131IO between solid Mg-Al-LDH-CO3...

  • High coercivity below percolation threshold in polymer nanocomposite. Shekhar, S.; Sajitha, E. P.; Prasad, V.; Subramanyam, S. V. // Journal of Applied Physics;Oct2008, Vol. 104 Issue 8, p083910 

    The magnetic properties of nanocomposites of polymer and magnetic (carbon cased iron carbide) nanoparticles have been studied from 300 to 10 K. The nanocomposites show an enhanced coercivity and they retain the magnetic properties at very low concentration of filler. The high coercivity is...

  • Thermopower of composites containing metallic cobalt nanoparticles embedded in the Al2O n dielectric matrix. Belousov, V. A.; Granovsky, A. B.; Kalinin, Yu. E.; Sitnikov, A. V. // Physics of the Solid State;Oct2007, Vol. 49 Issue 10, p1848 

    The concentration and temperature dependences of the thermopower of composites containing Co nanoparticles embedded in the Al2O n dielectric matrix are investigated. Below the percolation threshold, i.e., in the tunneling conduction region, the absolute values of the thermopower of the...

  • The influence of the concentration and size of silver nanoparticles on the conductivity of ring-shaped deposits resulting from evaporation of colloidal solution droplets. Vysotskii, V. V.; Uryupina, O. Ya.; Senchikhin, I. N.; Roldughin, V. I. // Colloid Journal;Nov2013, Vol. 75 Issue 6, p634 

    The conductivity of ring-shaped deposits formed at the periphery of evaporating droplets of silver nanoparticle colloidal solutions has been studied. The dependence of the resistance of the ring-shaped deposits on nanoparticle size has been shown to exhibit a percolation transition. The specific...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics