• Korean Journal of Materials Research
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• v.20 no.5
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• pp.241-245
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• 2010

One of the weak points of the Cr-doped SZO is that until now, it has only been fabricated on perovskite substrates, whereas NiO-ReRAM devices have already been deposited on Si substrates. The fabrication of RAM devices on Si substrates is important for commercialization because conventional electronics are based mainly on silicon materials. Cr-doped ReRAM will find a wide range of applications in embedded systems or conventional memory device manufacturing processes if it can be fabricated on Si substrates. For application of the commercial memory device, Cr-doped $SrZrO_3$ perovskite thin films were deposited on a $SrRuO_3$ bottom electrode/Si(100)substrate using pulsed laser deposition. XRD peaks corresponding to the (112), (004) and (132) planes of both the SZO and SRO were observed with the highest intensity along the (112) direction. The positions of the SZO grains matched those of the SRO grains. A well-controlled interface between the $SrZrO_3$:Cr perovskite and the $SrRuO_3$ bottom electrode were fabricated, so that good resistive switching behavior was observed with an on/off ratio higher than $10^2$. A pulse test showed the switching behavior of the Pt/$SrZrO_3:Cr/SrRuO^3$ device under a pulse of 10 kHz for $10^4$ cycles. The resistive switching memory devices made of the Cr-doped $SrZrO_3$ thin films deposited on Si substrates are expected to be more compatible with conventional Si-based electronics.

• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.25-28
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• 2022

We investigated the formation of superconducting intergrowth phases through the interface reaction both between TlSr₂Cu₁O₅ (Tl-121) and (CrO₄)Sr₂CuO₂, and between Tl -121 and ((CO₃)_0.5(CrO₄)_0.5 Sr₂CuO₂ phases. We found oxychromate intergrowth phases can be formed through the interface reactions and a new superconducting oxychromate compound TlSr₄Cu₂O_z(CO₃)_0.5(CrO₄)_0.5 with T_c above 73 K was discovered based on the results of the interface reactions.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.152-160
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• 1979

The promoting effect of Ba or Sr addition was investigated for furfural hydrogenation reaction over copper-chromium oxide catalysts. X-ray diffraction patterns showed the appearance of $BaCrO_4$ and $SrCrO_4$ phases in Ba, and Sr promoted copper-chromium oxide catalysts. For both Ba and Sr promoted catalysts, the activity decline with reaction time was much smaller compared to that of unpromoted catalyst and copper-chromium oxide catalyst dispersed on silica, reproducible EPR signals of Cr(V) were observed when CO was adsorbed. The promoting effect of Ba addition can be interpreted in terms of active sites dispersion and stabilization.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.11-16
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• 2019

$La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$(LSTF) coated $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$(BSCF) membranes which has properties of high oxygen permeability and stability to $CO_2$ were applied to a bench scale apparatus to conduct oxygen permeation experiments. Also, the membranes of the laboratory and the bench scale device were divided into three regions according to the temperature gradient in the membrane reactor for comparative analysis. While oxygen permeation experiment were conducted up to $900^{\circ}C$, temperature dependence of Cr deposition was investigated. As a result, it was confirmed that the oxygen permeability was $2.37ml/min{\cdot}cm^2$, which was significantly lower than $3.79ml/min{\cdot}cm^2$ measured in the laboratory apparatus. It was found through XRD and SEM/EDS analysis that the decrease in oxygen permeability was originated from the deposition of gaseous Cr on the membrane surface released from the alloy material of the housing. In particular, a large amount of Cr was found in the medium temperature region.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2761-2764
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• 2011

A new Ruddlesden-Popper phase $NdSr_2MnCrO_7$ has been prepared by the standard ceramic method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The electrical transport properties show that the phase is an electrical insulator and the electrical conduction in the phase occurs by a 3D variable range hopping mechanism. The magnetic studies suggest that the ferromagnetic interactions are dominant.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.697-702
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• 2011

The new layered perovskite manganites $La_{0.5}Sr_{1.5}Mn_{0.5}Cr_{0.5-x}Fe_xO_4$ (x=0.15, 0.3) have been prepared by standard ceramic method. The powder X-ray diffraction studies show that the phases crystallize with tetragonal unit cell in the space group I4/mmm. The electrical transport properties suggest that the phases show insulating behaviour and the electrical conduction in the phases occurs by a 3D variable range hopping mechanism. The magnetic properties suggest that both the phases are antiferromagnetic.

• Journal of Magnetics
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• v.8 no.4
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• pp.129-132
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• 2003

We investigated the crystallographic and magnetic properties of double perovskite $Sr_2Fe_{l-x}Cr_{x}MoO_{6}$ (x=0.0, 0.01, 0.03, 0.05, and 0.10). Mossbauer spectra of the $Sr_2Fe_{l-x}Cr_{x}MoO_{6}$ have been taken at various temperatures ranging from 15 to 415 K. As the temperature increased towards $T_{c}$(415 K), the Mossbauer spectra showed line broadening and 1, 6 and 3, 4 line-width differences because of anisotropic hyperfine field fluctuation. The Mossbauer spectra indicated that an anisotropic field fluctuation of +H ( $P_{+}$=0.85) was greater than that of -H ($P_{-}$=0.15). We also calculated the field fluctuation frequency factors and the temperature dependence of anisotropy energies from its relaxation rate. We interpreted the effect of Cr ($t^3$$_{2g}$) doping as a decrease in the anisotropy energy.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1135-1141
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• 2008

The $La_{1-x}(Ca\;or\;Sr)xCrO_3$(x=0 and 0.25) interconnect materials for high temperature electrolysis of steam were investigated in views of sinterability and electrical conductivity. $LaCrO_3$, $La_{0.75}Ca_{0.25}CrO_3$ (LCC), and $La_{0.75}Sr_{0.25}CrO_3$ (LSC) powders were synthesized by coprecipitation method. Crystal structure was confirmed by X-ray diffraction (XRD). The sintering characteristics were analyzed by relative density and scanning electron microscopy. The electrical conductivity was measured by a DC four probe method. From the analyses of relative densities, it was found that the doped $LaCrO_3$ showed better sinterability than $LaCrO_3$ and the those sinterability increased with decrease of those particle sizes. The XRD results at different sintering temperatures for LCC and LSC revealed that the sinterability is closely related to the second phase transformation, that is, the second phase melting above $1,300^{\circ}C$ for LCC and $1,400^{\circ}C$ for LSC significantly promotes the sinterability. In case of electrical conductivities of LCC and LSC, which had a similar relative density, LCC showed better electrical conductivity than LSC.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1921-1923
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• 2013

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.136.2-136.2
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• 2010

고전도성 세라믹 연결재용 $La_{0.8}Sr_{0.2}Cr_{1-x}Ti_xO_3$ (X=0.1 and 0.2) 연결재 재료의 소결도와 전기전도도에 대해서 연구하였다. 이러한 목적으로 $LaCrO_3$, $La_{0.8}Sr_{0.2}Cr_{0.8}Ti_{0.2}O_3$ (LSCT82), $La_{0.8}Sr_{0.2}Cr_{0.9}Ti_{0.1}O_3$ (LSCT91) 분말들을 공침법을 통해 합성하였으며, 결정구조는 X-ray Diffraction(XRD)를 통해 확인하였다. 소결 특성은 주사 전자현미경을 통해 분석하였고 전기 전도도는 직렬 4-단자 법으로 측정하였다. 상대 밀도 분석으로부터 도핑된 $LaCrO_3$는 $LaCrO_3$보다 더 높은 소결성을 나타내었고, 입자 크기가 작을수록 소결성이 향상하는 것을 확인 할 수 있었다. 다양한 소결온도에서 얻은 LSC, LSTC 시편들의 XRD 결과는 LSC와 LSTC의 소결성이 2차상의 상전이와 밀접한 관련이 있다는 사실을 나타내었다. 다시 말해, LSTC는 $1300^{\circ}$이상 LSC는 $1400^{\circ}C$ 이상에서 2차상이 융해됨으로써 소결성을 현저하게 향상시킨다는 것을 알 수 있었다. 그리고 비슷한 상대밀도를 가진 LSC와 LSTC의 전기 전도도를 비교 측정한 결과, LSTC가 LSC보다 더 높은 전기 전도도를 나타낸다는 것을 알 수 있었다.