Europium Oxide-Hematite Magnetic Ceramic Nanoparticles

MRS Advances ◽  
2015 ◽  
Vol 1 (3) ◽  
pp. 215-220 ◽  
Author(s):  
Monica Sorescu ◽  
Lucian Diamandescu ◽  
John DiGnazio ◽  
Tianhong Xu
Keyword(s):  
Milling Time ◽  
Mechanochemical Activation ◽  
Phase Evolution ◽  
Milling Process ◽  
Europium Oxide ◽  
Activation Process ◽  
Solid Solution Formation ◽  
Biomedical Sensing ◽  
Solution Formation ◽  
Nanoparticle System

ABSTRACTNanoparticle system with the composition xEu2O3-(1-x)α-Fe2O3 (x = 0.1 and 0.5) was successfully synthesized by mechanochemical activation of Eu2O3 and α-Fe2O3 mixtures for 0-12 hours of ball milling time. The study is of relevance to catalysis, biomedical, sensing and energy-related applications. 57Fe and 151Eu Mössbauer spectroscopy were used to investigate the phase evolution, solid solution formation and hyperfine parameters of xEu2O3-(1-x)α-Fe2O3 nanoparticle system under the mechanochemical activation process. The 57Fe Mössbauer studies showed that the spectrum of the ball milled samples evolved from a sextet for hematite to sextets and a doublet upon duration of the milling process with europium oxide. This indicated the formation of the EuFeO3 perovskite for large x values and long milling times. The 151Eu Mössbauer investigations showed that the isomer shift decreased with increasing milling time for all molar concentrations employed.

Structural, Magnetic and Hyperfine Properties of Molybdenum Dioxide-Hematite Mixed Oxide Nanostructures

MRS Advances ◽  
2018 ◽  
Vol 3 (47-48) ◽  
pp. 2887-2892
Author(s):  
Richard Trotta ◽  
Felicia Tolea ◽  
Mihaela Valeanu ◽  
Lucian Diamandescu ◽  
Agnieszka Grabias ◽  
...  
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Mechanochemical Activation ◽  
Magnetic Measurements ◽  
Activation Process ◽  
Zero Field ◽  
Molybdenum Dioxide ◽  
Nanoparticle System ◽  
Ball Milling Time ◽  
Field Cooling

ABSTRACTMoO2-Fe2O3 nanoparticle system was successfully synthesized by mechanochemical activation of MoO2 and α-Fe2O3 equimolar mixtures for 0-12 hours of ball milling time. The study aims at exploring the formation of magnetic oxide semiconductors at the nanoscale. X-ray powder diffraction (XRD), Mössbauer spectroscopy and magnetic measurements were used to study the phase evolution of MoO2-Fe2O3 nanoparticle system under the mechanochemical activation process. The Mössbauer studies showed that the spectrum of the mechanochemically activated composites evolved from a sextet for hematite to sextet and a doublet upon duration of the milling process with molybdenum dioxide. Recoilless fraction was determined using our dual absorber method and was found to decrease with increasing ball milling time. Magnetic measurements recorded at 5 and 300 K in an applied magnetic field of 50,000 Oe showed the magnetic properties in the antiferromagnetic and canted ferromagnetic states. The Morin transformation was evidenced by zero-field cooling-field cooling (ZFC-FC) measurements in 200 Oe and the transformation characteristic temperatures were shifted to lower values.

AEM investigation of ZrO2 solid solution formation in ZrO2/mullite composites

1984 ◽  
Vol 42 ◽  
pp. 408-409
Author(s):  
T. R. Dinger
Keyword(s):  
Solid Solution ◽  
Ion Beam ◽  
Analytical Electron Microscopy ◽  
Transformation Toughening ◽  
Solid Solution Formation ◽  
Solution Formation ◽  
Propagating Crack ◽  
Analytical Electron ◽  
Microcrack Toughening ◽  
Made In

Zirconia (ZrO2) is often added to ceramic compacts to increase their toughness. The mechanisms by which this toughness increase occurs are generally accepted to be those of transformation toughening and microcracking. The mechanism of transformation toughening is based on the presence of metastable tetragonal ZrO2 which transforms to the monoclinic allotrope when stressed by a propagating crack. The decrease in volume which accompanies this transformation effectively relieves the applied stress at the crack tip and toughens the material; microcrack toughening arises from the deflection of a propagating crack around sharply angular inclusions.These mechanisms, however, do not explain the toughness increases associated with the class of composites investigated here. Analytical electron microscopy (AEM) has been used to determine whether solid solution effects could be the cause of this increased toughness. Specimens of a mullite (3Al2O3·2SiO2) + 15 vol. % ZrO2 were prepared by the usual technique of mechanical thinning followed by ion beam milling. All observations were made in a Philips EM400 TEM/STEM microscope fitted with EDXS and EELS spectrometers.

SOLID SOLUTION FORMATION DURING LIQUID PHASE SINTERING

1986 ◽  
Vol 47 (C1) ◽  
pp. C1-441-C1-445
Author(s):  
E. KOSTIĆ ◽  
S. J. KISS ◽  
D. CEROVIĆ
Keyword(s):  
Solid Solution ◽  
Liquid Phase ◽  
Liquid Phase Sintering ◽  
Solid Solution Formation ◽  
Solution Formation

Development of Biodegradable Mg-Ti Alloy Synthesized Using Mechanical Alloying

2016 ◽  
Vol 1133 ◽  
pp. 75-79 ◽  
Author(s):  
Emee Marina Salleh ◽  
Sivakumar Ramakrishnan ◽  
Zuhailawati Hussain
Keyword(s):  
Mechanical Alloying ◽  
Milling Time ◽  
Milled Powder ◽  
Milling Process ◽  
Planetary Mill ◽  
Ti Alloy ◽  
X Ray Diffraction ◽  
Argon Flow ◽  
Diffraction Patterns ◽  
Ti Powder

The aim of this work was to study the effect of milling time on binary magnesium-titanium (Mg-Ti) alloy synthesized by mechanical alloying. A powder mixture of Mg and Ti with the composition of Mg-15wt%Ti was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 400 rpm for various milling time of 2, 5, 10, 15 and 30 hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400 MPa and sintered in a tube furnace at 500 °C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Ti solid solution when Mg-Ti powder was mechanically milled for 15 hours and further. Enhancements of Mg-Ti phase formation with a reduction in Mg crystallite size were observed with the increase in milling time. A prolonged milling time has increased the density and hardness of the sintered Mg-Ti alloy.

scholarly journals Mechanochemical Preparation of Slow Release Fertilizer Based on Glauconite–Urea Complexes

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507 ◽  
Author(s):  
Maxim Rudmin ◽  
Elshan Abdullayev ◽  
Alexey Ruban ◽  
Ales Buyakov ◽  
Bulat Soktoev
Keyword(s):  
Milling Time ◽  
Slow Release ◽  
Mechanochemical Activation ◽  
Structural Characteristics ◽  
Fluorescence Analysis ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Slow Release Fertilizers

We investigated the mechanochemical synthesis of complex slow release fertilizers (SRF) derived from glauconite. We studied the effectiveness of the mechanical intercalation of urea into glauconite using planetary and ring mills. The potassium-nitric complex SRFs were synthesized via a mechanochemical method mixing glauconite with urea in a 3:1 ratio. The obtained composites were analyzed using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence analysis, and infrared spectroscopy. The results show that as duration of mechanochemical activation increases, the mineralogical, chemical, and structural characteristics of composites change. Essential modifications associated with a decrease in absorbed urea and the formation of microcrystallites were observed when the planetary milling time increased from 5 to 10 min and the ring milling from 15 to 30 min. Complete intercalation of urea into glauconite was achieved by 20 min grinding in a planetary mill or 60 min in a ring mill. Urea intercalation in glauconite occurs much faster when using a planetary mill compared to a ring mill.

Structural basis of solid solution formation during chiral resolution

2000 ◽  
Vol 11 (20) ◽  
pp. 4061-4070 ◽  
Author(s):  
Orsolya Barabás ◽  
Dóra K Menyhárd ◽  
Zsolt Böcskei ◽  
Kálmán Simon ◽  
Ilona Kiss-Ajzert ◽  
...  
Keyword(s):  
Solid Solution ◽  
Chiral Resolution ◽  
Structural Basis ◽  
Solid Solution Formation ◽  
Solution Formation

Synthesis and sintering of nano-sized forsterite prepared by short mechanochemical activation process

2016 ◽  
Vol 678 ◽  
pp. 290-296 ◽  
Author(s):  
Mohammad Sadegh Abdi Maghsoudlou ◽  
Touradj Ebadzadeh ◽  
Zahra Sharafi ◽  
Marziyeh Arabi ◽  
Karim Rostami Zahabi
Keyword(s):  
Mechanochemical Activation ◽  
Activation Process
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