TY - JOUR
T1 - Scattering effect of the well-ordered MgB4 impurity phase in two-step sintered polycrystalline MgB2 with glycine addition
AU - Cai, Qi
AU - Liu, Yongchang
AU - Guo, Qianying
AU - Ma, Zongqing
N1 - Publisher Copyright:
© 2017, Springer-Verlag Berlin Heidelberg.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Glycine-doped MgB2 bulk was prepared by two-step sintering in this study, first at 750 °C and then 900 °C. The MgB4 particles are induced to precipitate where the dislocations concentrated after C substitution or along the steps of screw dislocation during crystal growth, forming ordered MgB4 arrays throughout the MgB2 grain. By means of atomic force microscope, the detected magnetic domains are arranged in agreement with the ordered MgB4 particles after the measurement of magnetic hysteresis loop, which supported that the nano-scale MgB4 domain structure brought strong scattering effects and indicated that atomic force microscopy could test the role of the impurities. As a result, the extrapolating upper critical field Hc2(0 K) is enhanced to 22.8 T for the sample with ordered MgB4, while only 18.1 T for the un-doped sample underwent the same sintering program. Besides, carbon substitution contributed to the enhancement of Hc2 as well.
AB - Glycine-doped MgB2 bulk was prepared by two-step sintering in this study, first at 750 °C and then 900 °C. The MgB4 particles are induced to precipitate where the dislocations concentrated after C substitution or along the steps of screw dislocation during crystal growth, forming ordered MgB4 arrays throughout the MgB2 grain. By means of atomic force microscope, the detected magnetic domains are arranged in agreement with the ordered MgB4 particles after the measurement of magnetic hysteresis loop, which supported that the nano-scale MgB4 domain structure brought strong scattering effects and indicated that atomic force microscopy could test the role of the impurities. As a result, the extrapolating upper critical field Hc2(0 K) is enhanced to 22.8 T for the sample with ordered MgB4, while only 18.1 T for the un-doped sample underwent the same sintering program. Besides, carbon substitution contributed to the enhancement of Hc2 as well.
UR - http://www.scopus.com/inward/record.url?scp=85014837865&partnerID=8YFLogxK
U2 - 10.1007/s00339-017-0855-z
DO - 10.1007/s00339-017-0855-z
M3 - Article
AN - SCOPUS:85014837865
SN - 0947-8396
VL - 123
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
IS - 4
M1 - 229
ER -