Fabrication of Stack-Structured Gas Sensor of LaCrxCo1-xO3/Li1.3Al0.3Ti1.7(PO4)3 and Its NOx Sensing Properties

LaCrxCo1-xO3/Li1.3Al0.3Ti1.7(PO4)3의 적층구조를 가지는 가스센서 제조와 그의 NOx 검지특성

  • Lee, Young-Sung (Department of Materials Engineering, Graduate School of PaiChai University) ;
  • Shimizu, Y. (Department of Applied Chemistry, Graduate School of Kyushu Institute of Technology) ;
  • Song, Jeong-Hwan (Department of Materials Engineering, Graduate School of PaiChai University)
  • 이영성 (배재대학교 대학원 재료공학과) ;
  • ;
  • 송정환 (배재대학교 대학원 재료공학과)
  • Received : 2015.07.22
  • Accepted : 2015.08.06
  • Published : 2015.08.27


Impedancemetric $NO_x$ (NO and $NO_2$) gas sensors were designed with a stacked-layer structure and fabricated using $LaCr_xCo_{1-x}O_3$ (x = 0, 0.2, 0.5, 0.8 and 1) as the receptor material and $Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ plates as the solid-electrolyte transducer material. The $LaCr_xCo_{1-x}O_3$ layers were prepared with a polymeric precursor method that used ethylene glycol as the solvent, acetyl acetone as the chelating agent, and polyvinylpyrrolidone as the polymer additive. The effects of the Co concentration on the structural, morphological, and $NO_x$ sensing properties of the $LaCr_xCo_{1-x}O_3$ powders were investigated with powder X-ray diffraction, field emission scanning electron microscopy, and its response to 20~250 ppm of $NO_x$ at $400^{\circ}C$ (for 1 kHz and 0.5 V), respectively. When the as-prepared precursors were calcined at $700^{\circ}C$, only a single phase was detected, which corresponded to a perovskite-type structure. The XRD results showed that as the Co concentration of the $LaCr_xCo_{1-x}O_3$powders increased, the crystal structure was transformed from an orthorhombic phase to a rhombohedral phase. Moreover, the $LaCr_xCo_{1-x}O_3$ powders with $0{\leq}x<0.8$ had a rhombohedral symmetry. The size of the particles in the $LaCr_xCo_{1-x}O_3$powders increased from 0.1 to $0.5{\mu}m$ as the Co concentration increased. The sensing performance of the stack-structured $LaCr_xCo_{1-x}O_3/Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ sensors was found to divide the impedance component between the resistance and capacitance. The response of these sensors to NO gas was more sensitive than that to $NO_2$ gas. Compared to other impedancemetric sensors, the $LaCr_{0.8}Co_{0.2}O_3/Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ sensor exhibited good reversibility and reliable sensingresponse properties for $NO_x$ gases.


  1. J. W. Fergus, Sens. Actuators, B, 121, 652 (2007).
  2. T. J. Koplin, M. Siemons, C. Ocen-Valentin, D. Sanders and U. Simon, Sensors, 6, 298 (2006).
  3. C. Wang, L. Yin, L. Zhang, D. Xiang and R. Gao, Sensors, 10, 2088 (2010).
  4. E. D. Bartolomeo, M. L. Grilli and E. Traversa, J. Electrochem. Soc., 151, H133 (2004).
  5. A. Dutta and T. Ishihara, Sens. Actuators, B, 108, 309 (2005).
  6. P. Elumalai, J. Wang, S. Zhuiykov, D. Terada, M. Hasei and N. Miura, J. Electrochem. Soc., 152, H95 (2005).
  7. Y. Shimizu, H. Nishi, H. Suzuki and K. Maeda, Sens. Actuators, B, 65, 141 (2000).
  8. D. Koba, S. Takase and Y. Shimizu, ECS Transactions, 3(10), 163 (2006).
  9. Y. S. Lee, Y. Shimizu and J. H. Song, Korean J. Mater. Res., 21(8), 468 (2011).
  10. J. I. Moon, H. C. Cho and J. H. Song, Korean J. Mater. Res., 22(7), 346 (2012).
  11. R. D. Shannon, Acta Crystallographica, A32, 751 (1976).
  12. H. P. S. Correa, C. O. Paiva-Santos, L. F. Setz, L. G. Martinez, S. R. H. Mello-Castanho and M. T. D. Orlando, Powder Diffraction Suppl., 23(2), S18 (2008).
  13. C. Gu, J. Huang, Y. Wu, M. Zhai, Y. Sun and J. Liu, J. Alloys Comp., 509, 4499 (2011).
  14. J. Zhao, Y. Liu, X. Li, G. Lu, L. You, X. Liang, F. Liu, T. Zhang and Y. Du, Sens. Actuators, B, 181, 802 (2013).
  15. D. E. Williams, Conduction and gas response of semiconductor gas sensors, in Solid State Gas Sensors, P. T. Moseley and B. C. Tofield (eds.), Adam Hilger, p. 71, Bristol, UK (1987).