资源描述：
《Dielectric Properties of Beta Barium Borate.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、Cryst.Res.Technol.2819935131-743C.RAMACHANDRARAJA,R.GOBINATHAN,F.D.GNANAMAlagappaCollegeofTechnology,AnnaUniversity,Madras,IndiaDielectricPropertiesofBetaBariumBorateandPotassiumPentaborateSingleCrystalsSinglecrystalsofbetabariumborateandpotassiumpentaborate(commonly
2、knownasb-BaB,O,orBBOandKB,O,.4H20orKB5)weregrownbyhighandlowtemperaturesolutiongrowthmethods,respectively.Thedielectricconstantandlosstangentweredeterminedasafunctionoftemperature.Frequencyresponseofthedielectricconstantandtan6havebeenstudiedoverafrequencyrangeof0.1-
3、100kHz;itisfoundthatboththedielectricconstantandtan6decreasewithincreaseinfrequencyforbothcrystals.Thedielectricconstantandtan6arefoundtoincreasewithincreaseintemperatureforboththecrystals.Further,thedielectricconstantandtan6measuredondifferentorientationsofthegrownc
4、rystalsrevealtheanisotropicnatureofthecrystals.IntroductionBBOandKB5aretwoimportantmaterialsfornon-linearopticalapplicationsinthevisibleandultravioletregions(CHENetal.;DEWEYetal..Bariumborateexhibitsareversiblephasetransitionat920Ifr5"C.Itshightemperaturephase(ol-BaB
5、,O,)belongstothespacegroupofR3c(MIGHELLetal.)withcentrosymmetry,whereasthelowtemperaturephase(P-BaB,O,)belongstothespacegroupofR3c(LIEBERTZ,STAHR).KB5belongstothespacegroupofC2v(COOK,JAFFE).Thispaperreportstheresultsofourmeasurementsofdielectricconstant(K)andlosstan6
6、ofBBOandKB5singlecrystals.BBOsinglecrystalshavebeengrownusingNa,Oasfluxtoavoidthe&$-phasetransition.KB5singlecrystalshavebeengrownbyreactingK2C0,andH3B03intripledistilledwater.Thefrequencyrangecoveredis0.1to100kHzandthetemperatureregion30-250"CforBBOand30-150"CforKB5
7、.Dielectricstudieshavebeenmadewiththeelectricfieldappliedparalleltotheabplane(K,,)andperpendiculartotheabplane(K33)ofBBO.ThetwoorientationsofKB5onwhichthedielectricstudieshavebeenmadeare(100)and(010).Asfarasisknowntotheauthors,suchadetailedstudyvaryingthetemperaturea
8、ndfrequencyonthesematerialshasnotyetbeenreported.ExperimentSincephasetransitionfroma-BaB,O,to/?-BaB,O,takesplaceat925&5"C,fluxtechn
