• Title, Summary, Keyword: Pyroelectric

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Effect of P(VDF/TrFE) Film Thickness on the Characteristics of Pyroelectric Passive Infrared Ray Sensor for Human Body Detection (P(VDF/TrFE) 필름의 두께에 따른 인체 감지형 초전형 PIR 적외선 센서의 특성)

  • Kwon, Sung-Yeol
    • Journal of Sensor Science and Technology
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    • v.20 no.2
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    • pp.114-117
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    • 2011
  • A thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated and then thin 1.6 ${\mu}m$ thickness P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated also. These thick and thin P(VDF/TrFE) film pyroelectric infrared ray sensor was mounted in TO-5 housing to detect infrared light of 5.5 ~ 14 ${\mu}m$ wavelength for human body detecting with each other. The noise output voltage of the thick P(VDF/TrFE) film pyroelectric infrared ray sensor were 380 mV and NEP(noise equivalent power) is $3.95{\times}10^{-7}$ W which is the similar value with the commercial pyroelectric infrared ray sensor using ceramic materials as a sensing material. The NEP and specific detectivity $D^*$ of the thin P(VDF/TrFE) film pyroelectric infrared ray sensor were $2.13{\times}10^{-8}$ W and $9.37{\times}106$ cm/W under emission energy of 13 ${\mu}W/cm^2$ respectively. These result caused by lower thermal diffusion coefficient of a thin 1.6 ${\mu}m$ thickness PVDF/TrFE film than the thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor.

Sintering Behavior, Dielectric and Pyroelectric Properties of $(Pb, La)TiO_3$ Ceramics ($(Pb, La)TiO_3$ 세라믹스의 소결 거동 및 유전.초전 특성)

  • 최동구;최시경
    • Journal of the Korean Ceramic Society
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    • v.31 no.8
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    • pp.841-848
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    • 1994
  • The sintering behavior of La-modified PbTiO3 ceramics was investigated in order to improve the poor sinterability of PbTiO3. Addition of La improved the sinterability. It was confirmed that this improvement was due to the decrease in tetragonality ratio c/a of crystal lattice. The variations of dielectric constant and pyroelectric coefficient were measured with temperature. It was observed that with the increase of La content, Curie temperature decreased and dielectric constant at room temperature increased. La-modified PbTiO3 ceramics had smaller pyroelectric figure of merits than those of pyroelectric materials in use. The effects of grain size on dielectric and pyroelectric properties were also investigated. The change of grain size had effect on maximum dielectric constant and pyroelectric coefficient, but is had little effect on pyroelectric figure of merit at room temperature. The closer examination near ferro-paraelectric phase transition temperature revealed that the behavior of phase transition approached a more relaxor character with the increase of La content and the decrease of grain size.

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Pyroelectric and pyromagnetic effects on behavior of magneto-electro-elastic plate

  • Kondaiah, P.;Shankar, K.;Ganesan, N.
    • Coupled systems mechanics
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    • v.2 no.1
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    • pp.1-22
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    • 2013
  • Under thermal environment, Magneto-Electro-Elastic (MEE) material exhibits pyroelectric and pyromagnetic effects which can be used for enhancing the performance of MEE sensors. Recently studies have been published on material constants such as pyroelectric constant and pyromagnetic constant for magneto-electro-thermo-elastic smart composite. Hence, the main aim of this paper is to study the pyroelectric and pyromagnetic effects on behavior of MEE plate under different boundary conditions subjected to uniform temperature. A numerical study is carried out using eight noded brick finite element under uniform temperature rise of 100 K. The study focused on the pyroelectric and pyromagnetic effects on system parameters like displacements, thermal stresses, electric potential, magnetic potential, electric displacements and magnetic flux densities. It is found that, there is a significant increase in electric potential due to the pyroelectric and pyromagnetic effects. These effects are visible on electric and magnetic potentials when CFFC and FCFC boundary conditions are applied. Additionally, the pyroelectric and pyromagnetic effects at free edge is dominant (nearly thrice the value in CFFC in comparison with FCFC) than at middle of the plate. This study is a significant contribution to sensor applications.

Pyroelectric and dielectric properties of the modified PZT thin films and bulk ceramics (Modified PZT계 박막과 bulk의 초전 및 유전특성 비교)

  • Kim, K.W.;Kang, D.H.;Shin, S.H.;Cho, S.C.;Kim, Y.H.;Gil, S.K.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.743-745
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    • 2002
  • Pyroelectric and dielectric properties of modified PZT thin film and bulk ceramics were studied. In case of bulk specimens were prepared by conventional ceramic process and thin films with same composition and (111) preferred orientation were prepared by the sol-gel process. Their crystal structure, pyroelectric and dielectric properties were investigated after poling at $150^{\circ}C$ for 30 min for bulk ceramics and no poling treatment, respectively. Dielectric constants and losses of bulk and thin film were 600, 875 and 0.028, 0.025, respectively. Pyroelectric coefficients obtained were $50nC/cm^2K$ and $30nC/cm^2K$, respectively.

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The Fabrication and Characteristics of 0-3 PbTiO$_3$/P(VDF/TrFE) Nanocomposite Thin Films for Passive Pyroelectric Infrared Sensors

  • Kwon, Sung-Yeol
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.2
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    • pp.73-76
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    • 2004
  • 0-3 PbTiO$_3$/P(VDF/TrFE) nanocomposite thin films for passive pyroelectric infrared sensors were fabricated by a two-step spin coating technique. 65wt% VDF and 35 wt% TrFE was formed into a P(VDF/TrFE) powder. Nano size PbTiO$_3$ powder was used. 0-3 connectivity of PbTiO$_3$/P(VDF/TrFE) composite film was successfully achieved and observed using SEM photography. The dielectric constant and pyroelectric coefficient were measured and compared with P(VDF/TrFE). A very low dielectric constant (13.48 at 1KHz and sufficiently high pyroelectric coefficient (3.101 nC/$\textrm{cm}^2$ㆍk at 5$0^{\circ}C$) were measured. This nanocomposite can be used for a new pyroelectric infrared sensor to achieve better performance.

Pyroelectric Characteristics of 0-3 PbTiO3/P(VDF/TrFE) Nanocomposites Thin Films for Infrared Sensing

  • Kwon, Sung-Yeol
    • Korean Journal of Materials Research
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    • v.17 no.4
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    • pp.236-238
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    • 2007
  • [ 0-3PbTiO_3/P$ ](VDF/TrFE) nanocomposites thin films for passive pyroelectric infrared sensor have been fabricated by two-step spin coating technique. 65 wt% VDF and 35 wt% TrFE was formed to a P(VDF/TrFE) poder Nano size $PbTiO_3$ powder was used. 0-3 connectivity of $PbTiO_3$(VDF/TrFE) composites film is achieved and also observed by SEM photography successfully. The dielectric constant, and pyroelectric coefficient measured and compared with P (VDF/TrFE). A very low dielectric constant (13.48 at 1 kHz) and high enough pyroelectric coefficient (3.101 $nC/cm^2$.k at $50^{circ}C$) neasured. This nanocomposites can be used for a new pyroelectric infrared sensor for better performance.

Improving Sensitivity of the Pyroelectric Infrared Flame Detector (초전형 적외선식 불꽃감지기의 감도특성 개선)

  • Song, Hyun Seon;Lee, Yeu Yong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.4
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    • pp.77-84
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    • 2015
  • PZT ceramics, usually used pyroelectric materials exhibited a relatively highly Curie temperture(Tc) of $250-450^{\circ}C$ and permittivity constant of 500-1600. In this paper, the pyroelectric infrared detectors are applied two different types of pyroelectric materials, that is tetragonal crystal of ferroelectric $PbTiO_3$ and rhombohedral crystal of $Pb(Zr,Ti)O_3$. PZT ceramics shows not only highly Curie temperture but also excellent pyro and piezoelectric properties at the Zr/Ti(=52/48) ratio. Therefor in this paper, the pyroelectric infrared detectors are applied PZT ceramics, and obtained sensitive sensing characteristics by expriment case studies.

Pyroelectric Properties of $Pb(Zn_{1/3}Nb_{2/3})O_3-Pb(Fe_{1/2}Nb_{1/2})O}3$ Ceramics ($Pb(Zn_{1/3}Nb_{2/3})O_3-Pb(Fe_{1/2}Nb_{1/2})O}3$ 계에서의 초전성질에 관한 연구)

  • 김정욱;최성철;이응상
    • Journal of the Korean Ceramic Society
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    • v.32 no.6
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    • pp.748-760
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    • 1995
  • Pyroelectric properties, figure of merits, and the other properties of the Pb(Zn1/3Nb2/3)O3-Pb(Fe1/2Nb1/2)O3 system, as expected to have excellent pyroelectric properties in the operating temperature range of pyroelectric type infrared sensor, were investigated. In the Pb(Zn1/3Nb2/3)O3-Pb(Fe1/2Nb1/2)O3 system, suppression of the pyrochlore phase depended on sintering condition, as like sintering temperature, holding time, sintering atmosphere. The specimen, sintered by the same composition atmosphere powder at 105$0^{\circ}C$ for 1.5h, possessed the best physical property. It was found that the piezoelectric parameters were mainly depended on the amount of spontaneous polarization and then the 0.2PZN-0.8PFN showed the best pyro- and piezoelectric properties. In terms of the experimental method, two pyroelectric-testing methods, i.e. static and dynamic methods, had a same tendency. Also the result of pyroelectric testing by the static method indicated that the diffuse phase transitiion resulted in the temperature difference of phase transition between dielectric constant and pyroelectric coefficient.

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Pyroeffects on Magneto-Electro-Elastic Sensor patch subjected to thermal load

  • Kondaiah, P.;Shankar, K.
    • Smart Structures and Systems
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    • v.19 no.3
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    • pp.299-307
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    • 2017
  • The magneto-electro-elastic (MEE) material under thermal environment exhibits pyroelectric and pyromagnetic coefficients resulting in pyroelectric and pyromagnetic effects. The pyroelectric and pyromagnetic effects on the behavior of multiphase MEE sensors bonded on top surface of a mild steel beam under thermal environment is presented in this paper. The aim of the study is to find out how samples having different volume fractions of the multiphase MEE composite behave in sensor applications. This is studied at optimal location on the beam, where the maximum electric and magnetic potentials are induced due to pyroelectric and pyromagnetic effects under clamped-free and clamped-clamped boundary conditions. The sensor which is bonded on the top surface of the beam is modeled using 8-node brick element. The MEE sensor bonded on mild steel beam is subjected to uniform temperature rise of 50K. It is assumed that beam and sensor is perfectly bonded to each other. The maximum pyroelectric and pyromagnetic effects on electric and magnetic potentials are observed when volume fraction is ${\nu}_f=0.2$. The boundary conditions significantly influence the pyroelectric and pyromagnetic effects on electric and magnetic potentials.

The Fabrication and Characteristics of the Pyroelectric IR Sensor using P(VDF/TrFE) Thin Films Fabricated by the Spin Coating Technique

  • Kwon, Sung-Yeol
    • KIEE International Transactions on Electrophysics and Applications
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    • v.12C no.4
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    • pp.225-228
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    • 2002
  • The pyroelectric sensor of P(VDF/TrFE) film as sensing materials has been fabricated and evaluated with another commercial pyroelectric sensor using ceramic materials for sensing, The device was mounted in TO-5 housing to detect infrared light of a 5.5~14 ${\mu}{\textrm}{m}$ wavelength. The NEP(noise equivalent power) and specific detectivity D* of the device were 2.13$\times$10$^{-8}$ W and 9.37 10$^{6}$ cm/W under emission energy of 13 ㎼/$\textrm{cm}^2$, respectively.