22423
Pt / TiO2 / Pt / Ti memristive devices were electrically formed to either the ON or OFF state using voltages of the same polarity but with different amplitudes .
 Chemical: Pt; Chemical: TiO2; Chemical: Pt; Chemical: Ti
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Pt; Chemical: TiO2; Chemical: Pt; Chemical: Ti