11113
MIEC materials have higher k * values than pure electronic conductors in the temperature range from 500 - 850 degrees C , demonstrating the importance of both electronic species and oxygen vacancies being present for surface exchange .
 Chemical: oxygen
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: oxygen