• Title/Summary/Keyword: Tantalum-doping

Search Result 3, Processing Time 0.016 seconds

Effects of Doping Elements and the Amounts of Oxygen/Nitrogen Contents in Final Nitrides on the Characteristics of Red Pigment of Tantalum Nitrides (Ta3N5) (적색 안료인 탄탈륨 질화물(Ta3N5)의 특성에 도핑 물질 및 최종질화물의 산소/질소 함량이 미치는 영향)

  • Park, Eun-Young;Pee, Jae-Hwan;Kim, Yoo-Jin;Cho, Woo-Seok;Kim, Kyeong-Ja
    • Journal of Powder Materials
    • /
    • v.16 no.6
    • /
    • pp.396-402
    • /
    • 2009
  • Tantalum nitrides ($Ta_3N_5$) have been developed to substitute the Cd based pigments for non-toxic red pigment. Various doping elements were doped to reduce the amount of high price Tantalum element used and preserve the red color tonality. Doping elements were added in the synthesizing process of precursor of amorphous tantalum oxides and then Tantalum nitrides doped with various elements were obtained by ammonolysis process. The average particle size of final nitrides with secondary phases was larger than the nitride without the secondary phases. Also secondary phases reduced the red color tonality of final products. On the other hand, final nitrides without secondary phase had orthorhombic crystal system and presented good red color. In other words, in the case of nitrides without secondary phases, doping elements made a solid solution of tantalum nitride. In this context, doping process controlled the ionic state of nitrides and the amount of oxygen/nitrogen in final nitrides affected the color tonality.

Effect of Ta-Substitution on the Ferroelectric and Piezoelectric Properties of Bi0.5/(Na0.82K0.18)0.5TiO3 Ceramics

  • Do, Nam-Binh;Lee, Han-Bok;Yoon, Chang-Ho;Kang, Jin-Kyu;Lee, Jae-Shin;Kim, Ill-Won
    • Transactions on Electrical and Electronic Materials
    • /
    • v.12 no.2
    • /
    • pp.64-67
    • /
    • 2011
  • The effect of Ta substitution on the crystal structure, ferroelectric, and piezoelectric properties of $Bi_{0.5}(Na_{0.82}K_{0.18})_{0.5}Ti_{1-x}Ta_xO_3$ ceramics has been investigated. The Ta doping resulted in a transition from coexistence of ferroelectric tetragonal and rhombohedral phases to an electrostrictive pseudocubic phase, leading to degradations of the remnant polarization, coercive field, and piezoelectric coefficient $d_{33}$. However, the electricfield-induced strain was significantly enhanced by the Ta substitution-induced phase transition and reached a highest value of $S_{max}/E_{max}$ = 566 pm/V under an applied electric field 6 kV/mm when 2% Ta was substituted on Ti sites. The abnormal enhancement in strain was attributed to the pseudocubic phase with high electrostrictive constants.

Comparative Study of Conventional and Microwave Sintering of Large Strain Bi-Based Perovskite Ceramics

  • Kang, Jin-Kyu;Dinh, Thi Hinh;Lee, Chang-Heon;Han, Hyoung-Su;Lee, Jae-Shin;Tran, Vu Diem Ngoc
    • Transactions on Electrical and Electronic Materials
    • /
    • v.18 no.1
    • /
    • pp.1-6
    • /
    • 2017
  • A comparative study of microwave and conventional sintering of lead-free $Bi_{1/2}(Na_{0.82}K_{0.18})_{1/2}TiO_3-BaZrO_3-CuO$ ceramics is presented. It was found that microwave sintering (MWS) can be successfully applied to the fabrication of large strain Bi-perovskite with electric field-induced strains comparable to those obtained with conventional sintering (CFS). Although MWS resulted in smaller grained microstructures than CFS, the ferroelectric properties were stronger in MWS-derived specimens than in the CFS-derived ones. The piezoelectric strain constant $d_{33}{^*}$ of the CFS-derived specimens reached a maximum value of 372 pm/V after sintering at $1100^{\circ}C$, whereas that of MWS-derived specimens peaked at $950^{\circ}C$ with a $d_{33}{^*}$ value of 324 pm/V.