• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.327-331
• /
• 1997

As demand for various kinds and small lot products has been increasing, batch annealing has been appreciated for its small restiction for the opteration. The cold spot of the coil is very important in the BAF(Batch annealing furnace) annealing process. Because of the annealing cycle time in the BAF, annealing was decided on the cold spot of the coil. So, we tested the effect,variation of cold spot, for hydrogen contents of atmospheric gas at the annealing furnace. As a result of several investigations. We confirmed the following characteristics ; after the heating and soaking,the cold spot of coil moved to 1/3 of coil thickness in the NHx atmospheric gas, but the mid point of the coil thickness is the cold spot in the Ax or .H/sub2. atmospheric gas. Therefore, the use of hydrogen instead of nitrogen as the protective gas,combined with high convection in batch annealing furnaces, has shown that considerable increases in furnace output and material quality are attainable. Owing to the low density, high diffusion and reducing character of hydrogen, a better transfer resulting in uniform material temperatures and improved coil surfaces can be achieved.

• Transactions of Materials Processing
• /
• v.13 no.8
• /
• pp.704-709
• /
• 2004

The effect of annealing temperature on microstructures and mechanical properties of the 5052 Al sheets rolled 88% reduction at cryogenic temperature was investigated for the annealing temperature of 150 ~ $300^{\circ}C$, in comparison with those rolled at room temperature. The presence of equiaxed grains, whose size is about 200nm in a diameter, was observed in the alloy deformed 88% and annealed $200^{\circ}C$ for an hour. When compared with the deformation at room temperature, the deformation at cryogenic temperature showed the higher strengths and equivalent elongation after annealing at the annealing temperature below $200^{\circ}C$. However, for annealing above $250^{\circ}C$ materials deformed at cryogenic temperature showed the lower strength than those deformed at room temperature. This behavior might be attributed to the higher rate of recrystallization and growth in materials deformed at cryogenic temperature during annealing, due to the lager density of dislocations accumulated during the deformation.

• Journal of the Korean Ceramic Society
• /
• v.43 no.9 s.292
• /
• pp.527-531
• /
• 2006

In order to study the influence of post-annealing treatment on the frequency characteristics of the Li doped ZnO(Li:ZnO) FBAR(Film Bulk Acoustic Resonator) device, we investigated the material and electrical properties of Li:ZnO films in the annealing temperature range from 300 to $500^{\circ}C$. In our samples, as annealing temperature was increased, Li:ZnO films showed the improvement of high c-axis orientation and resistance value with relieved stress and low surface roughness. In addition to, the return loss in the frequency property of fabricated FBAR was improved by annealing treatment from 24.9 to 29.8dB. From experimental results, the optimum post-annealing temperature for FBAR is $500^{\circ}C$ and it can obtain excellent Li:ZnO FBAR performance with stronger c-axis orientation, smoother surface, relieved stress, and lower loss factor.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.163-163
• /
• 2012

We observed strain evolution of P3HT crystals in P3HT:PCBM films and the effect of Al electrode on the evolution during real time annealing process. Based on simple assumptions, both relaxed lattice parameters and thermal expansion coefficient could be quantitatively determined. P3HT:PCBM films displayed tensile strain in as-prepared samples regardless of the presence of an Al layer. In the absence of Al layer, P3HT crystals showed only strain relaxation at an annealing temperature of $180^{\circ}C$. Meanwhile In the presence of an Al layer, the strain was relaxed and changed to compressive strain at around 120C annealing temperature, which indicated a tightening of the thiophene ring packing. These behaviors support the improved performance of devices fabricated by post annealing process.

• ETRI Journal
• /
• v.32 no.6
• /
• pp.932-939
• /
• 2010

In this paper, a fast migration method is proposed. Our method executes local relocation on a model placement where an additional module is added to it for modification with a minimum number of displacements. This method is based on mean-field annealing (MFA), which produces a solution as reliable as a previously used method called simulated annealing. The proposed method requires substantially less time and hardware, and it is less sensitive to the initial and final temperatures. In addition, the solution runtime is mostly independent of the size and complexity of the input model placement. Our proposed MFA algorithm is optimized by enabling module rotation inside an energy function called permissible distances preservation energy. This, in turn, allows more options in moving the engaged modules. Finally, a three-phase cooling process governs the convergence of problem variables called neurons or spins.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2000.04b
• /
• pp.458-465
• /
• 2000

In the field of structural optimization simulated annealing (SA) algorithm has widely been adopted as an optimizer with the positive features of SA such as simplicity of the algorithm and possibility of finding global solution However, annealing process of SA algorithm based on random generator with the zeroth order structural information requires a large of number of iterations highly depending on cooling schedules and stopping criteria. In this paper, MSA algorithm is presented in the form of two phase annealing process with the effective cooling schedule and stopping criteria. With the application to optimal seismic design of steel structures, the performance of the proposed MSA algorithm has been demonstrated with respect to stability and global convergence of the algorithm

• KIEE International Transactions on Electrophysics and Applications
• /
• v.3C no.2
• /
• pp.43-47
• /
• 2003

Lead zirconate titanate (PZT) thin films were fabricated by the pulsed laser ablation deposition (PLAD) method onto Pt/Ti/SiO$_2$/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The well-crystallized perovskite phase and the (101) preferred orientation were obtained by two-step annealing at the conditions of $650^{\circ}C$, 1 hour. It was found that the temperature for the pulsed laser ablated PZT films annealed via a two-step annealing process can be reduced 20$0^{\circ}C$ compared to that of the conventional three-step annealing temperature profile for enhancing the transformation of the perovskite phase. The remanent polarization and the coercive field of this film were about 20 $\mu$C/$\textrm{cm}^2$ and 46 kV/cm, while the dielectric constant and loss values measured at 1 KHz were approximately 860 and 0.04, respectively. The interesting phenomena of this film, such as vertical shift in hysteresis curve, are also discussed.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.8
• /
• pp.89-98
• /
• 1992

IIM(Implantation Into Metal) process usning Co silicides has been investigated to obtain ultra-shallow junctions less than 0.1$\mu$m. Rapid Thermal Annealing using halogen lamps was employed to form CoSi$_2$ and junctions simultaneously.. Resistivities of CoSi$_2$ were 13-17$\mu$ $\Omega$-cm. CoSi$_2$/p$^{+}$/Si and CoSi$_2$/n$^{+}$/Si junction were formed by diffusion of B and As, respectively, from Co film. It was found out that B and As were severely lost by the evaporation during high temperature annealing Therefore SiO$_2$ capping layers were introduced to prevent the evaporation of the implanted dopants from the films. Investigation of the behavior of dopants with respect to annealing time revealed that increasing the annealing time enhanced the diffusion of dopants into Si from CoSi$_2$.

• Journal of Magnetics
• /
• v.20 no.3
• /
• pp.207-210
• /
• 2015

Modifications in the structural and magnetic properties of co-precipitated cobalt ferrite nanoparticles can be accomplished by varying the annealing time periods during the synthetic process. Experimental results show that high-purity cobalt ferrite nanoparticles are obtained using a co-precipitation process. The dependence of the crystallite sizes on the annealing time was successfully demonstrated using XRD and SEM. Finally, vibrating sample magnetometer analyses show that the magnetic properties of the cobalt ferrite nanoparticles depend on their relative particle sizes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.9
• /
• pp.725-728
• /
• 2000

Ferroelectric thin film capacitors with high dielectric constant are important for the application of memory devices. In this work, We have systematically investigated the variation of grain sizes depending on the process condition of two-step process. Both in-situ annealing and ex-annealing have been compared depending on the annealing time. C-V measurement, ferroelectric properties, leakage current, XRD and SEM were performed to investigate the electircal properties and microstructural properties of Pb(La, Ti)O$_3$ films.