Investigation of graphene dispersion on thermoelectric, magnetic, and …
페이지 정보
본문
논문명 | Investigation of graphene dispersion on thermoelectric, magnetic, and mechanical properties of p-type Bi0.5Sb1.5Te3 alloys |
---|---|
저자 | Pathan Sharief, Babu Madavali, Sung Ho Song, Jin Kyu Lee, Ki Buem Kim, Jong Tae Kim, Dong Hwan Kim, Jun-Hyun Han, Soon-Jik Hong |
저널명 | Materials Chemistry and Physics |
게재년월 | 2021/3/23 |
Vol. pp |
In this research, polycrystalline p-type Bi0.5Sb1.5Te3 (BST)/x-wt% graphene (x = 0, 0.05, 0.1 and 0.2 wt%)
composite bulks were fabricated to systematically investigate the effect of graphene content on thermoelectric, as
well as magnetic and mechanical properties. The peaks corresponding to the D, G and 2D bands of graphene were
clearly identified with Raman spectroscopy, and revealed that graphene was well dispersed in the BST matrix.
The bulk fracture surfaces displayed randomly distributed grains and a progressive decrease in grain size, with
increasing graphene content in the composite samples. A dramatic reduction in thermal conductivity of about
10%, and 12% was achieved for the 0.1, and 0.2 wt% graphene dispersed Bi0.5Sb1.5Te3 samples, respectively, due
to the strong scattering of phonons at interfaces and fine grain boundaries. Thanks to the adequate power factor
and the reduction in thermal conductivity by the incorporated graphene, the 0.1 wt% graphene dispersed
Bi0.5Sb1.5Te3 sample showed the highest ZT value among all samples. Interestingly, a transformation from
diamagnetic to para/ferro magnetic properties was observed after graphene incorporation, using magnetic
hysteresis loops. Vickers hardness was also greatly improved, from 84.1 Hv to 103.8 Hv, and compressive
strength was also increased. It was concluded that enhanced mechanical properties of the Bi0.5Sb1.5Te3 alloys was
due to the strengthening effect of hierarchically structured graphene and reduced grain size