Exchange bias of CoO1−δ/(NiFe,Fe) system with blocking temperature beyond Néel temperature of bulk CoO

2015 ◽  
Vol 107 (17) ◽  
pp. 172404 ◽  
Author(s):  
S. L. Ding ◽  
R. Wu ◽  
J. B. Fu ◽  
X. Wen ◽  
H. L. Du ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Blocking Temperature ◽  
Neel Temperature ◽  
Néel Temperature

MAGNETIC PROPERTIES STUDY OF SOL–GEL SYNTHESIZED COBALT-DOPED ANATASE TiO2 NANOPOWDER

2011 ◽  
Vol 10 (04n05) ◽  
pp. 581-585
Author(s):  
BISWAJIT CHOUDHURY ◽  
AMARJYOTI CHOUDHURY ◽  
RAJENDRA K SINGH
Keyword(s):  
Magnetic Measurements ◽  
Anatase Phase ◽  
Sol Gel ◽  
Weak Ferromagnetism ◽  
Annealed Sample ◽  
Blocking Temperature ◽  
Neel Temperature ◽  
Néel Temperature ◽  
Tem Analysis ◽  
Key Factor

Co doped TiO2 nanopowder has been synthesized by a simple sol–gel route. XRD and TEM analysis confirms anatase phase of TiO2 with crystallite and particle sizes of 10 and 15 nm respectively. Presence of Co is confirmed by EDX. FTIR shows a slight shift in the Ti-O bonding vibration to lower frequency suggesting dopant incorporation on Ti site. For magnetic measurements the sample with dopant amount x = 0.075 is annealed both in vacuum and air. Weak ferromagnetism and a blocking temperature of 39 K is obtained for vacuum annealed sample while ferromagnetism is lost in the air annealed sample and shows only paramagnetic behavior. Temperature dependent magnetic measurements for air annealed sample shows antiferromagnetic behavior with a Neel temperature of 36.51 K. Here we report that oxygen vacancy and cobalt aggregates is a key factor for inducing ferromagnetism–superparamagnetism in vacuum annealed sample. Appearance of Neel temperature reveals the presence of antiferromagnetic Co3O4 which is the oxidation results of metallic Co or cobalt clusters present on host TiO2 surface.

scholarly journals Магнитные свойства двухфазных магнитных боросиликатных стекол, содержащих наночастицы beta-Fe-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- и Fe-=SUB=-3-=/SUB=-O-=SUB=-4-=/SUB=-

2020 ◽  
Vol 46 (16) ◽  
pp. 28
Author(s):  
С.А. Борисов ◽  
А.А. Набережнов ◽  
B. Nacke ◽  
A. Nikanorov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Fields ◽  
Fe3o4 Nanoparticles ◽  
Superparamagnetic Nanoparticles ◽  
Blocking Temperature ◽  
Neel Temperature ◽  
Specific Magnetization ◽  
Borosilicate Glasses ◽  
Néel Temperature ◽  
Two Phase

The magnetic properties of two-phase borosilicate glasses containing in the skeleton a mixture of β-Fe2O3 and Fe3O4 nanoparticles have been studied. The sizes of nanoparticles have been determined, the value of blocking temperature (TB ~ 330 K) for ensemble of superparamagnetic nanoparticles is obtained. It is shown that in the high applied magnetic fields the specific magnetization of these glasses increases sharply at approaching and below Neel temperature for the bulk β-Fe2O3.

Magnetic Properties of Ni-NiO (Ferromagnetic–Antiferromagnetic) Nanocomposites Obtained from a Partial Mechanochemical Reduction of NiO

2008 ◽  
Vol 8 (6) ◽  
pp. 2923-2928 ◽  
Author(s):  
J. Nogués ◽  
V. Langlais ◽  
J. Sort ◽  
S. Doppiu ◽  
S. Suriñach ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Ball Milling ◽  
Exchange Bias ◽  
Neel Temperature ◽  
Ni Nanoparticles ◽  
Néel Temperature ◽  
Field Cooling

The magnetic properties of ferromagnetic (FM)–antiferromagnetic (AFM), Ni-NiO, nanocomposites obtained from a reactive ball milling reduction of NiO in H2 atmosphere have been studied. The formation of ferromagnetic Ni from antiferromagnetic NiO can be accurately followed by the increase of the saturation magnetization. The microstructure of the nanocomposite, consisting of FM Ni nanoparticles embedded in an AFM NiO matrix leads to exchange bias effects, i.e., loop shifts and coercivity enhancement, after field cooling from above the Néel temperature of NiO.

Exchange bias in UO2/Fe3O4thin films above the Néel temperature of UO2

2014 ◽  
Vol 105 (12) ◽  
pp. 122405 ◽  
Author(s):  
E. A. Tereshina ◽  
Z. Bao ◽  
L. Havela ◽  
S. Daniš ◽  
C. Kuebel ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Neel Temperature ◽  
Néel Temperature

scholarly journals Exchange bias and enhancement of the Néel temperature in thinNiF2films

2004 ◽  
Vol 69 (21) ◽  
Author(s):  
Hongtao Shi ◽  
D. Lederman ◽  
K. V. O’Donovan ◽  
J. A. Borchers
Keyword(s):  
Exchange Bias ◽  
Neel Temperature ◽  
Néel Temperature

The effect of high pressure on the Néel temperature of-manganese

1971 ◽  
Vol 47 (2) ◽  
pp. K99-K101 ◽  
Author(s):  
A. Sawaoka ◽  
T. Soma ◽  
S. Saito ◽  
Y. Endoh
Keyword(s):  
High Pressure ◽  
Neel Temperature ◽  
Néel Temperature
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