Effect of samarium oxide on structural,optical and electrical properties of some alumino-borate glasses with constant copper chloride

The glass system under study was prepared and examined using the melt quenching procedures and XRD to emphasize the amorphous nature,respectively.Transmittance of the prepared solid glass system was performed by a spectrophotometer in wavelengths from 190 to 1099 nm.Using traditional techniques and standard formulas,the density,molar volume,refractive index,optical band gap and the optical filter characteristics were determined,then the influence of samarium oxide on some properties like the structure and optical,also the electrical properties were dissected.A novel formula was proposed to estimate the refractive index from the optical energy gap.The obtained samples are good optical filters especially the sample that contains 0.8 mol% of Sm2 O3.Also this sample has the utmost density,the least molar volume,the maximum transmittance,least refractive index,the highest optical band gap and the least dc conductivity.

Sm^(2+)ions boost ammonia electrooxidation reaction on samarium oxide anode for hydrogen generation in non-aqueous electrolyte

Ammonia has garnered recognition as a zero-carbon fuel due to its high-density hydrogen storage capacity and its convenience for storage and transportation.To address the challenges associated with the direct usage of ammonia,the development of NH_(3)-to-H_(2)conversion technologies has emerged as a promising and effective approach.Herein,we present for the first time that crystallized Sm_(2)O_(3−x)electrodes demonstrate high and stable electrocatalytic activities,including N_(2)evolution rate and Faradaic efficiency,for ammonia electrolysis in a non-aqueous electrolyte.It was observed that Sm^(2+)ions in samarium oxide play an indispensable role in the ammonia electrooxidation reaction on the anodes.Furthermore,the mechanism of ammonia electrooxidation has also been elucidated,laying the foundation for a better understanding of the relationship between local structure and electrochemical properties in order to facilitate research on Pt-free electrocatalysts for the electrolysis of ammonia into H_(2).

Electrical conductivity optimization of the Na3AlF6–Al2O3–Sm2O3 molten salts system for Al–Sm intermediate binary alloy production

Metal Sm has been widely used in making Al–Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al–Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant(CVCC) technique was used to measure the conductivity for the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3electrolysis medium in the temperature range from 905 to 1055°C. The temperature(t) and the addition of Al2O3(W(Al2O3)), Sm2O3(W(Sm2O3)), and a combination of Al2O3and Sm2O3into the basic fluoride system were examined with respect to their effects on the conductivity(κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature(t) and decreases with the addition of Al2O3or Sm2O3or both. We concluded that the optimal operation conditions for Al–Sm intermediate alloy production in the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3system are W(Al2O3) + W(Sm2O3) = 3wt%, W(Al2O3):W(Sm2O3) = 7:3, and a temperature of 965 to 995°C, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.

Preparation and Properties of Sm_2O_3 Doped Y_3Al_5O_(12) Powders

YAG powders with different Sm concentrations were synthesized by nitrate-citrate sol-gel combustion method. Phase evolution, morphology and luminescent properties of the obtained materials were characterized by XRD, FESEM, photoluminescent excited by purple light, respectively. Powder X-ray diffraction showed that cubic YAG∶Sm crystallites were directly obtained at 800 ℃ from amorphous materials. The crystallization stage was characterized by an exothermic peak of DSC curve at 910 ℃. FESEM micrographs revealed that the resultant phosphors were agglomerated with an average particle size of about 300 nm. The photoluminescence spectra excited by 405 nm wavelength showed several obvious emission bands located in the 550～700 nm, corresponding to 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 transitions of Sm3+ ions, respectively. For luminescence property, the emission intensity of YAG∶Sm powders varied with the Sm contents and reached the maximum at 3%(mole fraction) Sm.

Effects of Sm_(2)O_(3) addition on sintering behavior of pre-synthesized magnesia-rich magnesium aluminate spinel

The effects of Sm_(2) O_(3) as an additive on the densification of a pre-synthesized magnesia-rich spinel were investigated.The sintering behavior of the material was characterized by analyzing its dilatometric characteristics,linear shrinkage,bulk density,apparent porosity,phase structure,and micro structure.Moreover,the cold modulus of rupture(CMOR) and microhardness of the spinel were measured.The results show that samarium oxide reacts with the spinel to form SmAlO_(3)(a rare-earth aluminate) to improve the sintering performance and mechanical properties of the spinel. The formation of magnesite phases decreases the rupture strength of the spinel.However,this MgO phase is inlaid in spinel grains boundary,has a pinning effect which can improve the sinterability of the spinel.

Enhanced acetone sensing performance of nanostructured Sm2O3 doped SnO2 thick films

In the present work, we synthesized Sm2O3 doped SnO2 in order to prepare a selective acetone sensor with fast response, quick recovery and good repeatability. Pure as well as 2 mol.%, 4 mol.%, 6 mol.% and 8 mol.% Sm2O3 doped SnO2 nanostructured samples were synthesized by using a co-precipitation method. The characterization of the samples was done by thermogravimetric and differential thermo-gravimetric analysis（TG-DTA）, X-ray diffraction（XRD）, field emission gun-scanning electron microscopy（FEG-SEM）, energy dispersive analysis by X-rays（EDAX）, high resolution scanning electron microscopy（HR-TEM）, selected area X-ray diffraction（SAED）, Brunauer-Emmet-Teller（BET） and ultraviolet-visible-near infrared（UV-Vis-NIR） spectroscopy techniques. The gas response studies of liquid petroleum gas, ammonia, ethanol and acetone vapor were carried out. The results showed that Sm doping systematically lowered operating temperature and enhanced the gas response and selectivity for acetone. The response and recovery time for 6 mol.% Sm2O3 doped SnO2 thick film at the operating temperature of 250 °C were 15 and 24 s, respectively.