1. National Institute of Materials Physics, Atomistilor Street, No. 405A, MG 07, 077125 Magurele, Romania
2. HORIBA Jobin Yvon S.A.S., 6-18, Rue du Canal, 91165 Longjumeau, France
3. Department of Mechanics, University Politehnica of Bucharest, BN 002, 313 Splaiul Independentei, Sector 6, 060042 Bucharest, Romania