Excellent ethanol sensing properties based on Er
2
O
3
-Fe
2
O
3
nanotubes
*
Liu Chang-Bai
a)
, He Ying
b)
, Wang Sheng-Lei
a)
SEM images of pure α -Fe
2
O
3
((a) and (b)) and 3 wt% Er
2
O
3
-Fe
2
O
3
nanotubes ((c) and (d)).