Increase Of Y3 Research Articles

Effects of Y3+ on properties of electroless NiYP coatings

NiYP alloy coatings were prepared on the surface of sintered NdFeB magnets by electroless composite plating. The effects of Y3+ concentration on the deposition rate, surface morphologies, element contents and corrosion resistance were investigated. The results showed that the deposition rate of NiYP alloy coatings decreased with the increasing Y3+ concentration. A thin NiYP film with adsorbed rare earth yttrium could be formed at higher concentration, which reduced the number of catalytic sites on the surface of intered NdFeB magnets. With the increase in Y3+ concentration up to 6 mmol L− 1, the self-corrosion potential Ecorr of the electroless NiYP coatings in 3.5%NaCl solution increased from − 672 to − 513 mV, and the self-corrosion current density Icorr decreased from 28.81 to 1.15 μA cm− 2. The mechanisms of corrosion resistance of the electroless NiYP coatings modified by Y3+ addition were discussed.

Ferroelectric relaxor behavior and dielectric properties of La/Y co-doped (Ba0.9Ca0.1)(Zr0.2Ti0.8)O3 ceramics

The ferroelectric relaxor behavior and dielectric properties of La2O3 and Y2O3 co-doped (Ba0.9Ca0.1)(Zr0.2Ti0.8)O3 ceramics prepared by solid route were investigated. The phase structure, microstructures and dielectric properties of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and impedance analyzer respectively. The results show that La3+ ions and Y3+ ions substitute for A-sites ions and B-sites ions respectively to enter the unit cell maintaining the perovskite structure of solid solution, inducing inhomogeneous microstructure, smaller grain size and lower density, then resulting the occurrence of ferroelectric relaxor behavior. The relaxor behavior was observed in (Ba0.9Ca0.1)0.995La0.005(Zr0.2Ti0.8)O3–x mol% Y ceramics and the degree of ferroelectric relaxation behavior is enhanced with the increase of Y3+ ions concentration. The dielectric constant increases with x = 0.0–0.1 then decreases with further addition, the sample with x = 0.1 shows a giant permittivity (21,736) with lower dielectric loss (0.063) and could be an attractive material for ceramic capacitor applications.

Improvement of electrical characteristics in the solution‐processed nanocrystalline indium oxide thin‐film transistors depending on yttrium doping concentration

Y3+ (0, 6, 12, or 20 mol%)‐doped In2O3 (YInO; YIO) thin films were fabricated by the sol–gel spin‐coating technique, and they were used as the active layer of thin‐film transistor (TFT) devices. The YIO‐TFTs operate in the n‐channel enhancement mode and exhibit a well‐defined pinch‐off and saturation region. The Y3+ (12 mol%)‐doped In2O3 TFT possesses the optimal performance, and its field‐effect mobility in the saturated regime, threshold voltage, on–off ratio, and S factor are 0.95 cm2 V−1 s−1, 6.74 V, 1.55 × 105, and 2.37 V decade−1, respectively. The yttrium ion can act as the carrier suppressor to reduce the carrier concentration of In2O3 thin film because of its lower electronegativity (1.22) and standard electrode potential (−2.372 V). The carrier concentrations and conductivities of In2O3 thin films decrease from 2.5 × 1014 to 3.8 × 1011 cm−3, and 14.3 to 1.5 × 10−4 S m−1, respectively, with the increase of Y3+ doping concentrations from 0 to 12 mol%. In addition, the Y3+ (12 mol%)‐doped In2O3 thin film also possesses the minimal surface roughness (4.19 nm) and lowest trap states (1.07 × 1013). Therefore, by Y3+ doping the electrical properties of In2O3 thin films can be improved to match the basic requirement of the TFT devices.

Synthesis and Structural and Electrical Investigations of a Hexagonal Y1–xGdxInO3 (0.0 ≤ x ≤ 1.0) System Obtained via Metastable C-Type Intermediates

Detailed structural and electrical investigations were carried out on an A-site disordered hexagonal Y(1-x)Gd(x)InO3 (0.0 ≤ x ≤ 1.0) series synthesized by a self-assisted gel-combustion route. The phase relations show profound temperature dependence. The metastable C-type modification could be stabilized for all the compositions, which on further heating get converted to stable hexagonal polymorphs. The conversion temperature (C-type to hexagonal) was found to increase with an increase in Y(3+) content. The system was observed to be single-phasic hexagonal at 1250 °C throughout the composition range. Interestingly, the increase in planar bonds of InO5 polyhedra was found to be twice that of the apical bonds on Gd(3+) substitution. Careful Raman spectroscopic studies highlighted a definitive though subtle structural change from x = 0.7 onward. The same observation is also corroborated by the dielectric studies. Electric field-dependent polarization measurements showed the ferroelectric hysteresis loop for pure YInO3. The system transforms from ferroelectric in YInO3 to almost paraelectric for GdInO3. In the present study, XRD, Raman, and electrical characterizations in conjunction reveal that to tune the electrical properties of the hexagonal rare earth indates, the variation in tilting of InO5 polyhedra has to be influenced, which could not be brought about by isovalent A-site substitution.

Enhanced performance of indium zinc oxide thin film transistor by yttrium doping

The Y3+-doped indium zinc oxide thin film transistor devices were fabricated by the sol–gel spin-coating technique. The Y3+-doped indium zinc oxide thin film transistor operates in n-channel enhancement mode and exhibits a well-defined pinch-off and saturation region. Because yttrium ion possesses lower electronegativity (1.22) and standard electrode potential (−2.372V), it can act as the carrier suppressor to reduce the carrier concentrations of indium zinc oxide (In:Zn=1:1) thin films from 1.29×1020 to 3.05×1014cm−3 with the increase of Y3+ doping concentrations from 0 to 12mol%. In addition, Y3+ (12mol%)-doped indium zinc oxide thin film has the minimal surface roughness (1.067nm) and lowest trap states (5.14×1012cm−2). Therefore, Y3+ (12mol%)-doped indium zinc oxide thin film transistor possesses the optimum performance, and its field-effect mobility in the saturated regime, threshold voltage, on–off ratio, and S-factor are 4.76cm2/Vs, 4.3V, 1.32×106, and 2.9V/decade, respectively.

Effect of yttrium oxide addition on absorption and emission properties of bismuth-doped silicate glasses

Y/Bi co-doped silicate glasses were prepared, and the effects of Y2O3 on the absorption and emission properties were investigated by spectrum measurement. It was found that the absorption intensity in visible region decreases with increase of Y3+ concentration in (70–x)SiO2- xY2O3-30CaO-1.5Bi2O3 (x=0 mol.%, 1 mol.%, 3 mol.%, 5 mol.%, 7 mol.%) glasses. The emissions centered at 410, 630, 1200 and 1290 nm were observed under 280, 470, 514 and 808 nm excitation, respectively. The emission intensity had the similar change tendency in the visible and near infrared region. We also discussed the actual role of Y3+ ions playing in the visible and near infrared emissions of the silicate glasses.

Studies on the structure and transport properties for Y-doped La2/3Ca1/3MnO3 perovsksite manganate

The structure and transport properties of perovskite (La1-xYx)2/3Ca1/3 MnO3 (0≤x≤0.3) systems are systematically investigated. It is found that all the compounds show a single phase structure. With the increase of Y3+ doping content the metalinsulator transition temperature TMI(M—I) shifts to lower temperatures. While the relevant resistance peak ρp is sharply increased, for the sample of x=0.3, it has been enhanced by eight orders of magnitude larger than the non-doped sample(x=0.0). In these materials a large magnetoresistance effect has been observed under an external magnetic field. At the same time, it is also directly shown that the correlation between the transport properties and the variation of crystal structure from the experiment result. Based on the double exchange model and the variable-range-hopping(VRH) theory, the mechanism of the influence of Y doping for La in La2/3Ca1/3MnO3 systems is also discussed.