New Physics: Sae Mulli

Aims and Scope

The origin of New Physics: Sae Mulli (NPSM, ISO abbreviation: New Phys.: Sae Mulli.): Sae Mulli (새물리 in Korean characters means ‘new physics’) is the oldest Korean pure scientific journal. It was first published in 1961 just after the Korean War by the Korean Physical Society (KPS). The primary mission of Sae Mulli was to start building up Korean physics research community from almost nothing and in fact Sae Mulli had made tremendous contributions to the Korean science community. Through a peer-review system, Sae Mulli had continued elevating the level of scientific researches, consequently becoming a cornerstone of the economic miracle of Korea...

Editor-in-Chief : Sam Jin KIM
New Physics: Sae Mulli Editorial Board

pISSN : 0374-4914
eISSN : 2289-0041

Tel : +82-2-556-4737
Fax : +82-2-554-1643
E-mail: npsm@npsm-kps.org

Research Papers

Luminescence Properties and Phase Transition of the Gd$_2$(MoO$_4$)$_3$:Eu$^{3+}$ Phosphors Compared by Sintering Temperature

Sung Jae LEE, Jong Won CHUNG, Hyun Kyoung YANG*

Department of LED Convergence Engineering, Pukyong National University, Busan 48547, Korea

Eu$^{3+}$-doped Gd$_2$(MoO$_4$)$_3$ phosphors were synthesized by using a solid state reaction method. The crystal structure, surface morphology and luminescence properties of the Gd$_2$(MoO$_4$)$_3$:Eu$^{3+}$ phosphors were analyzed in terms of the sintering temperature. The phase transition from the $\alpha$ phase to the $\beta'$ phase of Gd$_2$(MoO$_4$)$_3$ was observed using X-ray diffraction patterns for sintering temperatures between 800 and 850 $^\circ$C. The $\beta'$-Gd$_2$(MoO$_4$)$_3$:Eu$^{3+}$ phosphors exhibits a strong excitation band from 230 to 350 nm due to charge transfer in the Gd$_2$(MoO$_4$)$_3$ host lattice. Because of the $f-f$ transition of Eu$^{3+}$ ions in $\beta'$-Gd$_2$(MoO$_4$)$_3$:Eu$^{3+}$ phosphors, the PL spectra of the phosphors exhibit a narrow emission at 550 nm for the $^5$D$_1$-$^7$F$_1$ transition and one at 590 nm for the $^5$D$_0$-$^7$F$_1$ transition. Also, the photoluminescence spectra of the phosphors showed a dominant luminescence at 615 nm. These results show that the Gd$_2$(MoO$_4$)$_3$:Eu$^{3+}$ phosphor can be applied as a red emitting phosphor in warm white light-emitting diodes (LEDs).

New Phys.: Sae Mulli 2018; 68: 963-968

Magnetoresistance due to the Plane Current Effect through the Gap Layer Between the High-Tc Superconductor Film and the Giant Magnetoresistance-Spin Valve Multilayer

Woo-Il YANG¹, Jong-Gu CHOI², Sang-Suk LEE*²

¹ Department of Applied Physics and Electronics, Sangji University, Wonju 26339, Korea

² Department of Oriental Biomedical Engineering, Sangji University, Wonju 26339, Korea

A giant magnetoresistance-spin valve (GMR-SV) multilayer of NiFe/CoFe/Cu/CoFe/IrMn/Ta was fabficated on a high-Tc superconductor Y$_1$Ba$_2$Cu$_3$O$_{7-x}$(YBCO) film using ion beam deposition. The inverse magnetoresistance characteristics of hybrid-type multilayer samples containing YBCO with a thickness of 300 nm and antiferromagnetic IrMn based on a GMR-SV with a thickness of 42.5 nm were investigated at liquid-nitrogen temperatures below the critical temperature. The magnetoresistance (MR) ratio of -9.3% could be explained by using the effect of the plane current passing through the gap layer between the high-Tc superconductor film and the GMR-SV film. The existence of a gap layer of about 9 nm in thickness was confirmed by using a scanning electron microscope (SEM) image of a cross section of the hybrid multilayer sample. We found that the output voltage could be derived from an equivalent circuit consisting of three resistances, those of the GMR-SV layer, the Gap layer, and the YBCO layer and that the out put voltage increased as the thickness of the gap layer and the supply current increased.

New Phys.: Sae Mulli 2018; 68: 950-956

New Phys.: Sae Mulli 2018; 68: 939~1040

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Research Papers

Calculation of the Secondary Electron Emission Coefficients of MgO, MgBeO, MgCaO, MgSrO and MgBaO Induced by Auger Neutralization of He$^+$, Ne$^+$, Ar$^+$ and Xe$^+$ Ions

Jong Wan LEE*

New Phys.: Sae Mulli 2018; 68: 939-944 https://doi.org/10.3938/NPSM.68.939