Phase transformation and magnetic properties of $Ni_xFe_{100-x}$ thin films deposited by a co-sputtering

동시 스퍼터링법으로 제조된 $Ni_xFe_{100-x}$ 박막의 상변화와 자기적 특성

  • Kang, Dae-Sik (Electronic Components Center, Optic & Electronic Ceramics Division, Korea Institute of Ceramic Engineering and Technology) ;
  • Song, Jong-Han (Electronic Components Center, Optic & Electronic Ceramics Division, Korea Institute of Ceramic Engineering and Technology) ;
  • Nam, Joong-Hee (Electronic Components Center, Optic & Electronic Ceramics Division, Korea Institute of Ceramic Engineering and Technology) ;
  • Cho, Jeong-Ho (Electronic Components Center, Optic & Electronic Ceramics Division, Korea Institute of Ceramic Engineering and Technology) ;
  • Chun, Myoung-Pyo (Electronic Components Center, Optic & Electronic Ceramics Division, Korea Institute of Ceramic Engineering and Technology)
  • 강대식 (한국세라믹기술원 광.전자세라믹본부 전자부품센터) ;
  • 송종한 (한국세라믹기술원 광.전자세라믹본부 전자부품센터) ;
  • 남중희 (한국세라믹기술원 광.전자세라믹본부 전자부품센터) ;
  • 조정호 (한국세라믹기술원 광.전자세라믹본부 전자부품센터) ;
  • 전명표 (한국세라믹기술원 광.전자세라믹본부 전자부품센터)
  • Published : 2009.12.31

Abstract

$Ni_xFe_{100-x}$ films with a thickness of about 100nm were deposited on Si(100) substrates at room temperature by a DC magnetron co-sputtering using Fe and Ni targets. Compositional, structural, electrical and magnetic properties of the films were investigated. $Ni_{67}Fe_{33}$, $Ni_{55}Fe_{45}$, $Ni_{50}Fe_{50}$, $Ni_{45}Fe_{55}$, $Ni_{40}Fe_{60}$ films are obtained by increasing the sputtering power of the Fe target. The films of x < 55 have BCC structure and show the phase transformation after annealing at the range of $300{\sim}450^{\circ}C$ for 2 h. On the other hand, the films of x < 50 have the mixed crystalline phases of BCC and FCC after the annealing treatment. The saturation magnetization was decreased initially by the phase transformation effect but then increased again after annealing at $450^{\circ}C$ due to the grain growth and crystallization of BCC phases.

Si(100) wafer에 증착된 박막의 조성에 따른 결정상과 자기적 특성을 평가하고자 동시 스퍼터링법을 이용하여 다양한 조성의 박막을 제조하여 그의 상변화와 자기적 특성을 평가하였다. Fe 타겟의 인가되는 출력의 변화로 $Ni_xFe_{100-x}$(40 < x < 67)의 박막을 증착시 x < 55인 경우 BCC상으로 증착이 되었으며 $300{\sim}450^{\circ}C$에서 2시간 열처리를 한 결과 BCC에서 FCC로의 상전이가 일어나는 것을 관찰 할 수 있었으나, x < 50에서는 열처리 후에도 BCC와 FCC가 혼재하여 나타나는 것을 알 수 있었다. 상변화로 인해 $M_s$가 감소하였으나 $450^{\circ}C$에서 열처리시 상전이가 일어나지 않은 BCC상들의 입성장 및 결정화로 다시 $M_s$가 증가하였다.

Keywords

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