earticle

영어

Powders of Mn1+xBi (0.0≤x≤0.3) alloys were produced by mechanical alloying method using a planetary ball mill. XRD, FESEM and EDS results revealed powders consisted of LTP MnBi and Bi phases, showing considerable portion of powders had sizes smaller than 0.5㎛ which is considered as single domain particle size. Magnetic properties of Mr=15.0 emu/g and Hc=10.0 kOe and (BH)max=5.34 MGOe were obtained at x=0.08. Mechanically milled powders showed rather high coercivities >10 kOe which is comparable with Yang’s results obtained through magnetic separation technique. Tablet shaped magnets were fabricated through spark plasma sintering (SPS) process and subsequently heat treated for 3 to 28 days at 250℃. As x increased, MnBi phase with grain sizes of about 30㎚ increased while Bi phase decreased. Remanent
magnetizations increased in general with x while coercivity stayed not much changed around 7.5 kOe. Magnetic properties as Mr=28.1 emu/g, Hc=5.7 kOe and (BH)max=2.4 MGOe were obtained at x=0.08 annealed for 14 days.

한국어

Mn1+xBi(0.0≤x≤0.3) 미세분말이 기계적 합금화 방법(MA)으로 제조하고 이 분말을 사용하여 스파크
플라즈마 소결법(SPS)으로 등방성 영구자석을 제조하였다. x=0.08일 때 미세분말은 잔류자화(Mr)가
15.0 emu/g, 보자력(Hc)이 10.0kOe이며 최대에너지적((BH)max)이 5.34 MGOe 이다. 특히, 보자력은
자기분리기술법(MST)을 사용하여 제조한 분말의 특성과 비슷한 값을 보여주었다. 스파크 플라즈마
소결법으로 제조한 등방성 영구자석은 보자력이 약 7.5 kOe 값을 보여주었다. x=0.08 에서 14일 동안
어닐링한 영구자석은 잔류자화(Mr)가 28.1 emu/g, 보자력(Hc)이 5.7 kOe 이며 최대에너지적 ((BH)max)이 2.4 MGOe 이다.