简介:Thephasesandmagnetocaloriceffectinthealloys(Gd1-xErx)5Si1.8Ge2.2withx=0,0.1,0.2and0.3wereinvestigatedbyX-raydiffractionanalysisandmagnetizationmeasurement.ThesamplesweresinglephasewiththemonoclinicGd5Si2Ge2-typestructure.WiththeincreaseofErcontent,theCurietemperature(Tc)decreasedobviouslyfrom253Kofthealloywithx=0to114Kwithx=0.3.Themaximummagneticentropychangedinthesamplesof(Gd1-xErx)5Si1.8Ge2.2withx=0.0,0.1,0.2and0.3were6.88,8.32,9.59and10.24J·kg-1·K-1respectivelyintheappliedfieldchangeof0~2.0T.
简介:AdetailedstudyofthefluorescenceemissionpropertiesandenergytransfermechanisminEr3+/Tm3+co-dopedleadsilicateglasseswasreported.Enhancednearinfrared1.8μmandvisibleup-conversionemissionswereinvestigatedunder808and980nmexcitations,respectively.TheenergytransfermechanismbetweenEr3+andTm3+wasanalyzedaccordingtotheabsorptionspectra,theemissionspectraandthelevelstructuresofEr3+andTm3+.TheenergytransferefficiencybetweenEr3+andTm3+reached68.1%intheEr3+/Tm3+co-dopedleadsilicateglasseswhenpumpedby808nmlaserdiode.Basedontheabsorptionspectra,theJudd-Ofeltparameters,spontaneousemissionprobability,absorptionandemissioncrosssections,gaincoefficientswerecalculatedandanalyzed.Itwasfoundthatthecalculatedemissioncrosssectionandthemaximumgaincoefficientaround1.8μmwere4.9×10–21cm2and1.12cm–1,respectively.TheseresultsindicatedthattheEr3+/Tm3+co-dopedlead-silicateglasseshadpotentialapplicationinnearinfraredlasers.