Addition Of Sm3 Research Articles

Crossrelaxations and non-radiative energy transfer from (4G5/2) Sm3+ → (5D0) Eu3+: B2O3–ZnO glasses

The present paper reports on the results concerning to photoluminescence features of Eu3+, Sm3+ ions and energy transfer process occurring from Sm3+ to Eu3+ doped in 45 B2O3–55 ZnO (BZn) glasses prepared by melt quenching technique. Luminescence quenching as a function of Eu3+ concentration in BZn glasses has been discussed. Among the studied concentrations, 0.5mol% of Eu3+ is optimized because it has exhibited red emission transition 5D0→7F2. With regard to Sm3+ glasses, orange emission at 602nm (4G5/2→6H7/2) has been noticed on exciting with λexci=403nm. Based on the Foster–Dexter theory, the possibility of energy transfer between Sm3+ and Eu3+ has been explained from the spectral overlap of Eu3+ absorption and Sm3+ emission. The optimized concentration 0.5mol% of Eu3+ is co-doped with Sm3+ in various concentrations ranging from 0.1 to 1.5mol% inorder to study the sensitization effect of Sm3+ on Eu3+ luminescence. The results have revealed that with the addition of Sm3+ to Eu3+: BZn glass, emission intensity of Eu3+ has been enhanced due to migration of Sm3+ excitation energy. Energy transfer based enhanced emission in the co-doped (Sm3++Eu3+): BZn glasses have been discussed accordingly from photoluminescence spectra, energy level diagram and lifetime measurements, colour coordinates and also the mechanism governing the energy transfer process has been explained in detailed. Colour coordinates for the co-doped glasses upon exciting at 403nm were also analysed. The results suggest that, the studied combination of rare earth ions could be promising candidates for red colour emitting LEDs in solid state lightning.

Concentration Effect of Sm3+ Ions on Structural and Luminescence Properties of Lithium Borate Glasses

Sm3+ containing lithium borate glasses successfully prepared and their physical and spectroscopic properties were analyzed. Addition of Sm3+ ions increases the density of glasses due to creation of BO−4 units. The absorption spectra of Sm3+ containing glasses show number of transition peaks as compared to base glass. Tau's method is employed to find the optical energy band gap of glasses. The value of optical energy band gap decreases with increase in Sm3+ content which is explained on the basis of structural changes. From the excitation spectra it is clear that these glasses can be easily excited by UV and near UV light. On excitation these glasses show strong emission at 598nm which corresponds to 4G5/2→6H7/2 transition. Luminescence results indicate that these glasses can be further modified for LED applications.

Electrical switching in cadmium ferrite with different rare-earth ions (Sm3+, Y3+, and La3+)

The cadmium ferrite and 5 % rare-earth ions (Sm3+, Y3+, and La3+) added Cd ferrites were synthesized by oxalate co-precipitation method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM) techniques. All ferrite samples under investigation exhibit current-controlled negative resistance type I–E characteristics at room temperature. The required electrical-switching field in cadmium ferrite is higher than that for 5 % Sm3+, Y3+, and La3+ added cadmium ferrites. The 5 % addition of Sm3+, Y3+, and La3+ in cadmium ferrite is found to decrease the grain size in this ferrite. This decrement in the grain size makes the required switching field to decrease in cadmium ferrite. No aging effect for electrical switching is observed in these ferrites.

Microstructures and High Frequency Properties of ${\hbox{Sm}}^{3+}$ Doped ${\hbox{Co}}_2{\hbox{Z}}$-Type Hexagonal Ferrites as Anti-EMI Magnetic Bead Materials

The Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> doped Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Z-type hexagonal ferrite materials were prepared by conventional ceramic method and characterized by techniques such as X-ray diffractometer and scanning electron microscopy. The influence of a small amount of Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> addition on structures and magnetic properties of the materials was investigated. The results show that Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Z-type hexaferrite is still in the main phase of the Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Z ferrite materials doped with Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> . It is observed that Sm-rich phase with granular morphology is dispersed in the main phase. The hysteresis measurement indicates that the specific saturation magnetization of Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> doped sample is bigger than that of the undoped one. The addition of Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> in Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Z ferrite can decrease the real part μ' and the imaginary part μ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">''</sup> of complex permeability, but increase significantly the cutoff frequency. The Sm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> doped Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Z ferrites sintered at 1250°C exhibited excellent high frequency properties such as high cutoff frequency above 1.8 GHz and higher initial permeability up to 5.

Effect of Simultaneous Substitution of Sm and Pr Ions on Dielectric and Ferroelectric Properties of Strontium Bismuth Titanate

Sr Smx Bi(4−x) Ti(4−y) Pry O15 (for x = 0, y = 0 and x = 0.1, y = 0, 0.1 and 0.2 and also for x = 0.2, y = 0.1) ceramics were prepared by Sol-gel Pechni method. Single phase of compounds was confirmed by XRD analysis and Lattice parameters were calculated. Microstructure and chemical analysis were performed using SEM and EDS techniques. The effect of addition of Sm3+ and Pr3+ ions on dielectric and polarization properties of Sr Bi4 Ti4 O15 was studied and shift in transition temperature was observed. The dc conductivity of the samples measured as a function of temperature.

Microestrutura e propriedades magnéticas de ferritas Ni-Zn-Sm

Pós nanométricos de ferritas Ni-Zn-Sm foram sintetizados por reação de combustão usando a uréia como combustível. O efeito da substituição dos íons de Fe3+ por Sm3+ na microestrutura e parâmetros magnéticos do sistema Ni0,5Zn0,5Fe2-xSm xO4 com x = 0,0; 0,05; 0,075 e 0,1 mol % de Sm3+ foi investigado. Os pós foram compactados uniaxialmente e sinterizados a 1200 °C/2 h com taxa de aquecimento de 5 °C/min. As amostras foram caracterizadas por medidas de densidade aparente, densidade relativa, difração de raios X, microscopia eletrônica de varredura e medidas magnéticas B-H. Os resultados evidenciam que a substituição dos íons Fe3+ por Sm3+ aumentou a densidade relativa de 95,4% para 100,0% da densidade teórica, reduziu o tamanho de grão de 2,87 para 0,62 mm e resultou em propriedades magnéticas adequadas para magnetos intermediários, atuando com bons absorvedores de radiação eletromagnética na faixa de microondas.