摘要
Thecreationandpropagationoflongitudinalacousticphonons(LAPs)inhighqualityhematitethinfilms(α-Fe2O3)epitaxiallygrownondifferentsubstrates(BaTiO3,SrTiO3,andLaAlO3)areinvestigatedusingthefemtosecondpump–probetechnique.Transientreflectionmeasurements(?R/R)indicatethephoto-excitedelectrondynamics,andtheinitialdecaylessthan1psandtheslowdecayof~500psareattributedtotheelectron-LOphononcouplingandelectron–holenonradiativerecombination,respectively.LAPsinα-Fe2O3filmcanbecreatedbyultrafastexcitationoftheligandfieldstate,suchastheligandfieldtransitionsunder800-nmexcitationaswellastheligandtometalcharge-transferwith400-nmexcitation.Thestrainmodulationsofthesoundvelocityandtheout-of-planeelasticpropertiesaredemonstratedinα-Fe2O3filmondifferentsubstrates.
出版日期
2014年04月14日(中国期刊网平台首次上网日期,不代表论文的发表时间)