Structural andopticalstudiesofFeSb2 under highpressure
Résumé
NanostructuredorthorhombicFeSb2 wasformedalongwithanamorphousphase,bymechanical alloyingfromamixtureofFeandSbpowders.Theinfluenceofpressureonthestructuralandoptical propertiesofthematerialwasinvestigatedbyX-raydiffraction(XRD)andRamanspectroscopy(RS)up to 28.2and45.2GPa,respectively.Thevolumefractionoftheamorphousphaseincreasedwith increasingpressure.Forpressuresabove14.3GPa,atetragonalFeSb2 phase wasalsoobserved.Forthe orthorhombicFeSb2 phase,thepressuredependenceofthevolumefittedtoaBirch-Murnaghan equationofstategaveabulkmodulus B0¼75.573.2 GPa,anditsderivative B0 0¼7.270.7. Forthe orthorhombicFeSb2 phase,theRamanactive A2 g modewasobservedupto28.3GPa,whilethe B21 g mode was notforpressureslargerthan14GPa.Forpressuresabove21GPa,theRamanactive A1g mode ofa tetragonalFeSb2 phase wasobserved