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Full-Text Articles in Engineering
Increased Radiative Lifetime Of Rare Earth-Doped Zinc Oxyhalide Tellurite Glasses, David L. Sidebottom, Michael A. Hruschka, B. G. Potter, Richard K. Brow
Increased Radiative Lifetime Of Rare Earth-Doped Zinc Oxyhalide Tellurite Glasses, David L. Sidebottom, Michael A. Hruschka, B. G. Potter, Richard K. Brow
Materials Science and Engineering Faculty Research & Creative Works
We have investigated the structural and optical properties of rare earth-doped zinc tellurite glasses modified by the substitution of ZnF2. Raman and phonon sideband spectroscopies were employed to characterize changes in the glass structure as well as to probe vibrational behavior in the immediate vicinity of the rare earth ion. These measurements are combined with photoluminescence and optical absorption to monitor the effect of halide substitution upon the optical behavior of the rare earth dopant. A substantial increase in the intrinsic radiative lifetime of Nd3+ is observed with increasing halide concentration.
Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr
Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr
Materials Science and Engineering Faculty Research & Creative Works
Glass ribbon-reinforced transparent polymer composites which provide excellent optical transparency and a low distortion level over a wide temperature range while exhibiting superior mechanical properties as compared to non- reinforced polymer counterparts, and equivalent properties as compared to glass fiber-reinforced counterparts.
Strip Casting With Fluxing Agent Applied To Casting Roll, Robert S. Williams, Ronald J. O'Malley, Richard C. Sussman
Strip Casting With Fluxing Agent Applied To Casting Roll, Robert S. Williams, Ronald J. O'Malley, Richard C. Sussman
Materials Science and Engineering Faculty Research & Creative Works
A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed …
Aluminum Nitride-Compatible Thick-Film Binder Glass And Thick-Film Paste Composition, Douglas M. Mattox
Aluminum Nitride-Compatible Thick-Film Binder Glass And Thick-Film Paste Composition, Douglas M. Mattox
Materials Science and Engineering Faculty Research & Creative Works
Mixed alkaline earth boroaluminate glasses comprising BaO combined with at least one of CaO, SrO and MgO. The glasses are useful as frit binders in aluminum nitride- compatible, thick-film paste compositions used in thick-film printing of hybrid microelectronic circuits on aluminum nitride substrates.
The Structure And Electrical Properties Of Srce0.95yb0.05o3 Thin Film Protonic Conductors, Igor Kosacki, Harlan U. Anderson
The Structure And Electrical Properties Of Srce0.95yb0.05o3 Thin Film Protonic Conductors, Igor Kosacki, Harlan U. Anderson
Materials Science and Engineering Faculty Research & Creative Works
The results of a study of the structure and electrical properties of SrCe0.95Yb0.05O3 thin film protonic conductors are presented. Dense SrCe0.95Yb0.05O3 thin films (∼1000 nm) with grain size in the 30-70 nm range were obtained on Si- and Al2O3-substrates using a polymeric precursor spin coating technique. The electrical conductivity of these thin films has been studied as a function of temperature and correlated with the microstructure. The thin films showed higher electrical conductivity than dense sintered polycrystalline SrCe0.95Yb0.05O3 specimens which had grain size in the micrometer range. This electrical conductivity enhancement has been attributed to the influence of interfacial grain …
Spin Dynamics Of Er³⁺ In Erba₂Cu₃O7-Δ, Suntharalingam Skanthakumar, Jeffrey W. Lynn, Fatih Dogan
Spin Dynamics Of Er³⁺ In Erba₂Cu₃O7-Δ, Suntharalingam Skanthakumar, Jeffrey W. Lynn, Fatih Dogan
Materials Science and Engineering Faculty Research & Creative Works
Neutron scattering techniques are used to study the magnetic excitations of the Er ions in superconducting ErBa2Cu3O7, a system where the Er ions order antiferromagnetically at TN=0.62 K and the sublattice magnetization obeys the relation for a 2D S=1/2 Ising model. Our data, which were taken on a cold neutron triple axis spectrometer using a horizontally focusing analyzer, reveal that there is a large gap of about 0.20 meV in the excitation spectrum, about four times the thermal energy kTN, as expected for an Ising system. However, we also observe …
Scaling Parallels In The Non-Debye Dielectric Relaxation Of Ionic Glasses And Dipolar Supercooled Liquids, David L. Sidebottom, Peter F. Green, Richard K. Brow
Scaling Parallels In The Non-Debye Dielectric Relaxation Of Ionic Glasses And Dipolar Supercooled Liquids, David L. Sidebottom, Peter F. Green, Richard K. Brow
Materials Science and Engineering Faculty Research & Creative Works
We compare the dielectric response of ionic glasses and dipolar liquids near the glass transition. Our work is divided into two parts. In the first section we examine ionic glasses and the two prominent approaches to analyzing the dielectric response. The conductivity of ion-conducting glasses displays a power law dispersion σ(ω)∞ωn, where n≈0.67, but frequently the dielectric response is analyzed using the electrical modulus M*(ω) = 1/ε*(ω), where ε*(ω) = ε(ω) - iσ(ω)/ω is the complex permittivity. We reexamine two specific examples where the shape of M*(ω) changes in response to changes in (a) temperature and (b) ion concentration, to …
Chemical Durability Of Lead-Oxide-Based, Thick-Film Binder Glasses, Douglas M. Mattox, Joshua H. Robinson
Chemical Durability Of Lead-Oxide-Based, Thick-Film Binder Glasses, Douglas M. Mattox, Joshua H. Robinson
Materials Science and Engineering Faculty Research & Creative Works
Lead-oxide-bearing glasses are incompatible with aluminum nitride metallization's, and federal legislation is recommending their replacement in thick-film electronics and labeling. To evaluate alternatives, the benchmark chemical durability's of the lead borosilicate and lead aluminate thick-film binder glasses have been determined. Aluminum oxide (Al2O3) benefits water durability moderately, acid durability substantially, and basic durability indistinguishably. The rate of attack in water is approximately two orders of magnitude greater than for soda-lime glass. The thermal contractions of the glasses are compatible. An apparent, spontaneous phase separation in the Al2O3-free glass is suppressed by Al2O3 that is included as a batch component.
Ferroelectric Films As A Fashion Object For Polycrystalline Film Investigation, V. Petrovsky, Harlan U. Anderson, M. Shumsky
Ferroelectric Films As A Fashion Object For Polycrystalline Film Investigation, V. Petrovsky, Harlan U. Anderson, M. Shumsky
Materials Science and Engineering Faculty Research & Creative Works
BaxSr1-xTiO3 (BST), PbZrxTi1-xO3 (PZT) and two-layer PZT-BST films were prepared on Pt, Si(100) and Si(111) substrates by a sol-gel method. XRD analysis shows that the PZT films on the Si(111) substrates tended to be preferentially oriented in the (110) direction. The nondestructive readout of the state of ferroelectric polarization was investigated by three methods: the pyroelectric effect, the non-linearity of the capacitance and the field effect in MOS structures. It is shown that all three methods provide nondestructive readout, and the choice between them depends on the intended use.
The Effect Of Casting Shape And Size On Solidification Time: A New Approach, Murat Tiryakioǧlu, Ergin Tiryakioǧlu, Donald R. Askeland
The Effect Of Casting Shape And Size On Solidification Time: A New Approach, Murat Tiryakioǧlu, Ergin Tiryakioǧlu, Donald R. Askeland
Materials Science and Engineering Faculty Research & Creative Works
The limitations of Chvorinov's Rule for predicting the solidification time of a casting are discussed and previous studies intended to modify Chvorinov's Rule in order to express the effect of the size and shape of castings on solidification time are reviewed. A new model that introduces a shape factor is presented that predicts the solidification times of castings as well as or better than Chvorinov's Rule, particularly for more complex shapes. The validity of the new model is compared with the conventional Chvorinov's Rule by a statistical analysis of twelve sets of data obtained from the literature.
Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris
Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris
Materials Science and Engineering Faculty Research & Creative Works
Interaction parameters for Mn-based alloys were evaluated using both carbon solubility and activity data for species in binary and ternary manganese alloys. The parameters at 1400 °C are the following εcc = -4.5; εccc = 58.8; εFeCC = 1.5; εFeCC = 2.5; In γC0 = -1.15 . εsisi = 15.5; εsisisi = 2.69; εFeSi = 2.5; εcsi = 12.4; εccsi = 27.5; In γSi0 = -7.46 The unified interaction parameter model (UIPM) was used to calculate the activity coefficients of species and the solubility of carbon in ferromanganese alloys (up to quaternary Mn-Fe-C-Si). The results were in good agreement with …