https://doi.org/10.1140/epjb/e2011-20728-2
Regular Article
Modulation of specific heat in graphene by uniaxial strain
1
MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of
Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an
710049, P.R.
China
2
Center on Experimental Physics, School of Science, Xi’an Jiaotong
University, Xi’an
710049, P.R.
China
3
Department of Applied Physics, School of Science, Xi’an Jiaotong
University, Xi’an
710049, P.R.
China
a e-mail: xiamg@mail.xjtu.edu.cn
Received:
2
September
2011
Received in final form:
15
October
2011
Published online:
23
November
2011
The specific heat of uniaxially strained graphene was investigated in the present paper. A uniaxial strain can modulate specific heat depending on the amount and direction of the strain. Specific heat decreases with an increase in the amount of tension strain at a low temperature and increases with compression. Above 110 K, it varies as the amount of strain is reversed to that at a low temperature. These novel properties can be attributed to the strain-induced shift behavior of out-of-plane acoustic phonons, which is different from that of other phonons. When the strain shifts from zigzag to armchair direction, specific heat gradually decreases for a given temperature. However, the variation in specific heat with the strain direction is significantly less than that with the amount of strain. Further, the difference in specific heat between different strain directions decreases with an increase in temperature. This tunable specific heat may provide a new route for both the implementation of thermal memory and the thermal management of graphene nanoelectronic devices.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2011
