Friday, 29 July 2011

Vortex control in PacMan nanodots

Control of vortex chirality and polarity in magnetic nanodots with broken rotational symmetry.
V. Cambel, and G. Karapetrov
Phys. Rev. B 84, 014424 (2011)
Hysteresis curve of a “Pac-Man”-like Py nanodot with an outer diameter of 70 nm, an inner diameter of 46 nm,
and a thickness of 40 nm.

SG behavior and Kondo effect

Kondo effect and spin-glass behavior of dilute iron clusters in silver films.
W. T. Herrera, Y. T. Xing, S. M. Ramos, P. Munayco, M. B. Fontes, E. M. Baggio-Saitovitch, and F. J. Litterst
PRB 84, 014430 (2011)
Onset temperature Ton for spin freezing, derived from resistivity data, for samples prepared at 285 K.

EB coupling in individual Co clusters

Bistable Coupling States Measured on Single Co Nanoclusters Deposited on CoO(111).
D. Le Roy, R. Morel, S. Pouget, A. Brenac, L. Notin, T. Crozes, and W. Wernsdorfer
Phys. Rev. Lett. 107, 057204 (2011)
Switching curves at 40 mK for one single nanocluster, after three successive coolings. The
dashed line is the easy axis direction and the dot indicates the bias field. Also shown is the CoO[10-1]direction.

Reorientation transition in NiO film

Continuous spin reorientation transition in epitaxial antiferromagnetic NiO thin films.
J. Li, E. Arenholz, Y. Meng, A. Tan, J. Park, E. Jin, H. Son, J. Wu, C. A. Jenkins, A. Scholl, H. W. Zhao, Chanyong Hwang, and Z. Q. Qiu
Phys. Rev. B 84, 012406 (2011)
(a) Schematic drawing of the measurement condition. (b) XAS from the Ni L2 edge and Fe magnetic hysteresis
loops from the Fe XMCD measurement. (c) L2 ratio versus the polarization angle. The result shows that the NiO in-plane spin component decreases to zero as the MgO thickness increases to 35 ML.

Ferromagnetism of free clusters

Metastability of Free Cobalt and Iron Clusters: A Possible Precursor to Bulk Ferromagnetism.
Xiaoshan Xu, Shuangye Yin, Ramiro Moro, Anthony Liang, John Bowlan, and Walt A. de Heer
Phys. Rev. Lett. 107, 057203 (2011)
P(M) for Co and Fe clusters for various thermalization conditions. Amplitudes are represented in color (blue:
low; red: high).

Tuesday, 26 July 2011

Quantum effects in magnetoreception

Sustained Quantum Coherence and Entanglement in the Avian Compass.
Erik M. Gauger, Elisabeth Rieper, John J. L. Morton, Simon C. Benjamin, and Vlatko Vedral
Phys. Rev. Lett. 106, 040503 (2011)
According to the RP model, the back of the bird’s eye contains numerous molecules for magnetoreception. These molecules give rise to a pattern, discernible to the bird, which indicates the orientation of the field.

Self-assembly of NPs: A Review

Directed self-assembly of Nanoparticles.
Marek Grzelczak, Jan Vermant, Eric M. Furst,, and Luis M. Liz-Marzán
ACS Nano 7, 3591 (2010)

Monday, 25 July 2011

Magnetization relaxation from firts principles

First-principles calculations of magnetization relaxation in pure Fe, Co, and Ni with frozen thermal lattice disorder.

Yi Liu, Anton A. Starikov, Zhe Yuan, and Paul J. Kelly
Phys. Rev. B 84, 014412 (2011)
Calculated Gilbert damping and resistivity for bcc Fe, hcp Co, and fcc Ni as functions of the rms displacements
measured in units of the corresponding lattice constants, a.

Friday, 22 July 2011

Tunable disorder in magnonics

Magnonic Crystal as a Medium with Tunable Disorder on a Periodical Lattice.
J. Ding, M. Kostylev, and A. O. Adeyeye
Phys. Rev. Lett. 107, 047205 (2011)
(a): SEM image of the CPW line and of two nanowires arrays (inset). (b): SEM image of the alternating
width nanowire array (w1= 260 nm, w2= 220 nm and edgeto-edge separation g = 60 nm). (c): Full loop 2D FMR absorption
spectra for the array. (d): Normalized M-H loop for the array.

Bloch points

Magnetization structure of a Bloch point singularity.
R.G. Elías and A. Verga
EJPB 82, 159 (2011)
Comparison of the Bloch point evolution with fixed magnetization at the surface of a sphere of radius
larger than the exchange length R = 20 nm; times are: (left) t = 0, (middle) t = 80 ps, and (right) t = 160 ps.

Thursday, 21 July 2011

Co NPs capped with Pt

Tuning the magnetic properties of Co nanoparticles by Pt capping.
A. Ebbing, O. Hellwig, L. Agudo, G. Eggeler, and O. Petracic
Phys. Rev. B 84, 012405 (2011)
ZFC/FC in-plane measurements of M vs T at the same field of H = 20 Oe for samples with constant tCo = 0.66 nm and various tPt = 0, . . ., 0.53 nm as indicated in the legend.

science (application/pdf Object)

On the magnetostatics of chains of magnetic nanoparticles.
C. Phatak , R. Pokharel , M. Beleggia , M. De Graef
JMMM, 323, 2912 (2011)
Schematic showing the geometry of straight chains of cubes (a),spheres(b),cylinders(c),bi-cones(d),octahedra(e),tetrahedra(f),andcuboctahedra (g);(h)shows a schematic of a bent chain o fparticles.

Decoherence in molecular manets

Decoherence in crystals of quantum molecular magnets.
S. Takahashi, I. S. Tupitsyn, J. van Tol, C. C. Beedle, D. N. Hendrickson & P. C. E. Stamp
Nature 476, 76 (2011)
Calculated contributions to the decoherence coming from the
coupling to nuclear spins, phonons and magnons. a, The three individual
contributions which sum to give the dimensionless decoherence rate cw5B/
T2Do, as a function of the qubit splitting in the case H\E^x.


Tuesday, 19 July 2011

Chain model for DW

Disordered chain model of cross tie wall spacing.
Zoe Budrikis, R. L. Stamps, Nils Wiese, and John Chapman
Phys. Rev. B 84, 024423 (2011)
Images generated in OOMMF of the magnetization configurations of cross tie domain walls (a) in equilibrium
spacing and (b) with one vortex displaced.

2D dipolar frustrated FM

Inverse transition in a two-dimensional dipolar frustrated ferromagnet.
Sergio A. Cannas, Marianela Carubelli, Orlando V. Billoni, and Daniel A. Stariolo
Phys. Rev. B 84, 014404 (2011)
Monte Carlo phase diagram h vs temperature
for the dipolar Heisenberg model with δ = 3 and η = 8.

Deppining of DW

Static and dynamic depinning processes of a magnetic domain wall from a pinning potential.
Ung-Hwan Pi,* Young-Jin Cho, Ji-Young Bae, Sung-Chul Lee, and Sunae Seo,
Phys. Rev. B 84, 024426 (2011)
Color-coded histogram of AMR difference between before and after the application of the nucleation current
pulse, i.e., Delta=AMR (after current pulse), − AMR (before current pulse).

Spin transfer from first principles

Nonlinear bias dependence of spin-transfer torque from atomic first principles.
Xingtao Jia, Ke Xia, Youqi Ke, and Hong Guo
Phys. Rev. B 84, 014401 (2011)
Sketch of a Fe/MgO/Fe(001) MTJ having seven MgO layers.

Interacting AFM particles

Slow dynamics of interacting antiferromagnetic nanoparticles.
Sunil K. Mishra and V. Subrahmanyam
Phys. Rev. B 84, 024429 (2011)

A comparison of the ZFC curves for all the interacting cases.

Saturday, 16 July 2011

LaFeO3 NPs

Surface and shape anisotropy effects in LaFeO3 nanoparticles.
Dan Wang and Menglian Gong
JAP 109, 114304 (2011)
Hysteresis loops for the LaFeO3 nanospheres and nanotubes measured
at 2 K (a) and 293 K (b). The inset shows the enlargement of the low field data.

Friday, 15 July 2011

FeO/Au NPs

Iron oxide nanoparticles coated with gold: Enhanced magnetic moment due to interfacial effects.
S. Banerjee, S. O. Raja, M. Sardar, N. Gayathri, B. Ghosh, and A. Dasgupta
JAP 109, 123902 (2011)

TEM of the (a) Sample B (Low-Au) and (b-d) Sample C (High-Au)
nanocomposites. Core(Fe3O4)-shell(Au) structures seen in Sample C
are shown in (c) and (d).

Review on Magnetic nanostructures

Magnetic nanostructures for advanced technologies: fabrication, metrology and challenges.
June W Lau and Justin M Shaw
J. Phys. D 44, 303001 (2011)



X-Ray Diffraction Microscopy of Magnetic Structures

X-Ray Diffraction Microscopy of Magnetic Structures.
Joshua J. Turner, Xiaojing Huang, Oleg Krupin, Keoki A. Seu, Daniel Parks, Stephen Kevan, Enju Lima, Kim Kisslinger, Ian McNulty, Richard Gambino, Stephane Mangin, Sujoy Roy, and Peter Fischer
PRL 107, 033904 (2011)

Spintronics with molecular nanomagnets

Graphene Spintronic Devices with Molecular Nanomagnets.
Andrea Candini, Svetlana Klyatskaya, Mario Ruben, Wolfgang Wernsdorfer, and Marco Affronte
nl2006142 (application/pdf Object)

Thursday, 14 July 2011

Colloidal self-assembly to 3D nanolithography

From Two-Dimensional Colloidal Self-Assembly to Three-Dimensional Nanolithography.
C.-H. Chang, L. Tian, W. R. Hesse, H. Gao, H. J. Choi, J.-G. Kim, M. Siddiqui, and G. Barbastathis
Nano Lett. 11, 2533 (2011)

FeO NPs for Hyperthermia

Water-Dispersible Sugar-Coated Iron Oxide Nanoparticles. An Evaluation of their Relaxometric and Magnetic Hyperthermia Properties.
Lenaic Lartigue, Claudia Innocenti, Thangavel Kalaivani, Azzam Awwad, Maria del Mar Sanchez Duque, Yannick Guari, Joulia Larionova, Christian Guérin, Jean-Louis Georges Montero, Véronique Barragan-Montero, Paolo Arosio, Alessandro Lascialfari, Dante Gatteschi, and Claudio Sangregorio
JACS 133, 10459 (2011)