• 제목/요약/키워드: LaNiO3 thin films

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Effect of Substrates on Structural and Electrical Properties of Chemical Solution Derived LaNiO3 thin Films

  • Lee, Hyung-Min;Hwang, Kyu-Seog;Lee, Kyong-Moo;Kim, Byung-Hoon
    • The Korean Journal of Ceramics
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    • 제4권3호
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    • pp.231-234
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    • 1998
  • LaNiO3 thin films were fabricated on various substrates by spin-coating technique using metal naphthenates as starting materials. Highly-oriented LaNiO3 films with smooth and crack-free surfaces were grown on SrTiO3 (100) and LaAlO3(100) substrates, while films on MgO(100) and Si(100) substrates showed random orientation. In this study, we concluded that lattice-mismatches between LaNiO3 films and substrates used affect film's properties.

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MOD법으로 제작한 $Bi_{3.25}La_{0.75}Ti_3O_{12}/LaNiO_3$ 박막의 강유전 특성에 관한 연구 (Ferroelectric properties of $Bi_{3.25}La_{0.75}Ti_3O_{12}/LaNiO_3$ thin films prepared by metalorganic decomposition method)

  • 김경태;김창일;김태형;이철인
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.352-355
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    • 2003
  • [ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the LaNiO3 (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thin films were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization $P_r$ and coercive field were $23.5\;{\mu}C/cm^2$ and 120 kV/cm, respectively.

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졸-겔법으로 $LaNiO_3$ 전극에 증착된 $(Na_{0.5}Bi_{0.5})TiO_3$ 박막의 배향성 (Orientation of $(Na_{1/2}Bi_{1/2})TiO_3$ thin films deposited on $LaNiO_3$ electrodes by sol-gel methode)

  • 박민석;유영배;문병기;손세모;정수태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.894-897
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    • 2004
  • Sodum bismuth titanate $(Na_{0.5}Bi_{0.5}TiO_3$ or NBT) thin films coated on the $LaNiO_3$ (LNO) electrode by sol-gel methode and rapid thermal annealing (RTA) technique. The NBT (NBT/LNO/Si) thin films examined by x-ray diffraction (XRD). The orientation of NBT was observed for films coated at $900^{\circ}C$, 5 min and $600^{\circ}C$, 60 min. Filed emission scanning electron microscopy (FE-SEM) showed uniform surface composed of grains. The grain size of NBT thin films increased with increasing annealing temperature.

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초고주파 응용을 위한 (100) 방향으로 성장된 PST / $LaNiO_3$박막의 구조적, 유전적 특성 (Dielectric and Structural properties of highly oriented $PST/LaNiO_3$ Thin Films for Microwave application)

  • 엄준철;이성갑;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.648-651
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    • 2004
  • Pb0.5Sr0.5TiO3(PST) thin films were deposited on the LaNiO3 (LNO(100))/Si and Pt/Ti/SiO2/Si substrates by the alkoxide-based sol-gel method. Structural and dielectric properties of PST thin films for the tunable microwave device applications were investigated. The PST films, which were directly grown on the Pt/Ti/SiO2/Si substrates showed the random orientation. For the LNO/Si substrates, the PST thin films exhibited highly (100) orientation. Compared with randomly oriented films, the highly (100)-oriented PST thin films showed better dielectric constant, tunability, and figure of merit (FOM). The dielectric constant, tunability, and FOM of the highly (100)-oriented PST thin film increased with increasing annealing temperature due to the decrease in lattice distortion. The differences in dielectric properties may be attributed to the change in the film stress and the in-plane oriented Polar axis depending on the substrate was used. The dielectric constants, dielectric loss and tunability of the PST thin films deposited on the LNO/Si substrates measured at 1 MHz were 483, 0.002, and 60.1%, respectively.

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$Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ 박막의 구조 및 강유전 특성에 미치는 $LaNiO_3$전극의 영향 (Effect of $LaNiO_3$ electrodes on Structural and Ferroelectric Proerties of $Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ Thin films)

  • 김경태;김창일;이철인;김태형
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.75-78
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    • 2004
  • $Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ (BET) thin films were deposited on the $LaNiO_3$ (LNO (100))/Si and Pt/Ti/$SiO_2$/Si substrates by the metal-organic decomposition method. Structural and dielectric properties of BLT thin films for the applications in nonvolatile ferroelectric random access memories were investigated. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures $650^{\circ}C$, the BET thinfilms were successfully deposited on LNO bottom electrode and exhibited (001) and (117) orientation. Compared with the Pt electrode films, the BET thin films on the LNO electrode annealed at $650^{\circ}C$ showed better dielectric constantsand remanent polarization. The BET thin films on the LNO electrode for the annealing temperature of $650^{\circ}C$, the remanent polarization Pr and coercive field were $45.6\;C/cm^2$ and 171 kV/cm, respectively.

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열처리조건이 LaNiO3 졸-겔 박막의 배향성과 구조 및 저항성에 미치는 영향 (Effect of Heat-treatment Conditions on Orientation, Structures and Resistances of LaNiO3 Thin Films by Sol-gel process)

  • 박민석;김대영;서병준;김강언;정수태
    • 한국전기전자재료학회논문지
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    • 제17권8호
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    • pp.859-865
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    • 2004
  • LaNiO$_3$(LNO) thin films on (100) Si substrates are prepared by sol-gel method on heat treatment conditions, such as heat transfer direction, pyrolysis and annealing process, and annealing temperatures and times. The effect of heat treatment conditions on the (100) orientations, structures and resistances of the thin films are investigated by XRD, SEM(FESEM), and a lout probe method. Highly (100) orientation factor(0.97), a pseudocubic crystalline structure with a dense and uniform microstructure could be formed by the following conditions: 1) the heat transfer direction is from Si substrate to LNO, 2) the pyrolysis and annealing process are alternated, 3) the annealing temperature is $650^{\circ}C$ and 4) the annealing times is 3 minutes. The sheet resistance of thin films decreased with increasing of a annealing temperature and time, and a number of coating.

temperature synthesis and ferroelectric properties of (117)-oriented $Bi_{3.25}La_{0.75}Ti_3O_{12}$ thin films on $LaNiO_3$ electrodes

  • Kim, Kyoung-Tae;Kim, Chang-Il
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.264-267
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    • 2004
  • [ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the $LaNiO_3$ (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thinfilms were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization Pr and coercive field were $23.5\;C/cm^2$ and 120 kV/cm, respectively.

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P-type Electrical Characteristics of the Amorphous La2NiO4+δ Thin Films

  • Hop, Dang-Hoang;Lee, Jung-A;Heo, Young-Woo;Kim, Jeong-Joo;Lee, Joon-Hyung
    • 한국표면공학회지
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    • 제51권4호
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    • pp.231-236
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    • 2018
  • We report p-type electrical characteristics of the amorphous $La_2NiO_{4+{\delta}}$ thin films which were sputtered on the glass substrates using an RF sputtering system. As-deposited thin films at room temperature and $300^{\circ}C$ were amorphous in nature. Post-annealing of the thin film samples over $400^{\circ}C$ resulted in the nano-crystallization of the $La_2NiO_{4+{\delta}}$. The electrical properties of the films were much dependent on the oxygen partial pressure, temperature of the post-annealing and sputtering ambient. The as-deposited samples at room temperature show a hole concentration of $7.82{\times}10^{13}cm^{-3}$, and it could be increased as high as $3.51{\times}10^{22}cm^{-3}$ when the films were post-annealed in an oxygen atmosphere at $500^{\circ}C$. Such p-type conductivity behavior of the $La_2NiO_{4+{\delta}}$ films suggests that the amorphous and nano-crystallized $La_2NiO_{4+{\delta}}$ films have potential for the application as p-type semiconductive or conductive materials at low temperatures where material diffusion is limited.

LaNiO3의 (100)배향성이 Pb(Zr,Ti)O3 박막의 결정성장과 강유전성에 미치는 영향 (Effects of (100) Orientation of LaNiO3 on the Growth and Ferroelectric Properties of Pb(Zr,Ti)O3 Thin Films)

  • 박민석;서병준;유영배;문병기;손세모;정수태
    • 한국전기전자재료학회논문지
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    • 제18권4호
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    • pp.338-343
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    • 2005
  • Pb(Zr,Ti)O₃[PZT] thin films were prepared on a highly (100) oriented LaNiO₃[LNO] and a randomly oriented LNO by sol-gel process. The PZT thin films on a highly (100) oriented LNO show a high (100) crystal orientation (F=100 %), those on a randomly oriented LNO show a random crystal orientation (F=60 %). All the PZT layer have a flat and dense microstructure with large columnar grains and their grain size are 25 nm. In the ferroelectric curves at electric field of 40 kV/cm, a highly (100) oriented PZT/LNO samples show coercive field, E/sub c/=10 kV/cm and remanent polarization, P/sub r/=14.5 μC/㎠, while a randomly oriented PZT/LNO sample show E/sub c/=10 kV/cm and P/sub r/=5.4 μC/㎠.

Si와 $Al_2O_3$ 기판에 대한 $LaNiO_3$ 박막의 배향성 형성과 도전도 (Formation and conductivity of oriented $LaNiO_3$ thin films on Si and $Al_2O_3$ substrates)

  • 김대영;박민석;손세모;이명교;김강언;정수태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.799-802
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    • 2003
  • [ $LaNiO_3$ ](LNO) thin films were deposited on various substrates as Si and $Al_2O_3$ by sol-gel process using lanthanum nitrate and nickel acetate. The structure and orientation of the films were characterized by X-ray diffraction. The orientation factors of films on Si(100), Si(111), $SiO_2/Si(100)$ and $Al_2O_3$were 97%, 63%, 73%, and 24% respective. The conductivity was $7.6{\times}10^{-3}{\Omega}{\cdot}cm$ with 10 times coating at Si(100) substrate.

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