Designation:A883/A883M–01StandardTestMethodforFerrimagneticResonanceLinewidthandGyromagneticRatioofNonmetallicMagneticMaterials1ThisstandardisissuedunderthefixeddesignationA883/A883M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemeasurementoftheferri-magneticresonancelinewidthandgyromagneticratioofiso-tropicmicrowaveferrites.Thistestisrestrictedtosphericalspecimenspossessingresonancelinewidthsgreaterthan10Oe[796A/m].1.2Thevaluesandequationsstatedincustomary(cgs-emuandinch-pound)orSIunitsaretoberegardedseparatelyasstandard.Withinthisstandard,SIunitsareshowninbrackets.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnoncon-formancewiththisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.SummaryofTestMethods2.1Ferritematerials,ingeneral,exhibitatmicrowavefre-quenciesapowerlossorabsorptionwhichisafunctionofanappliedDCmagneticfield.Inmanyferrites,thisdependenceisofasimpleform,havingasinglemaximumatsomevalueofthemagneticfield,whichdependsonthemicrowavefrequencyandonthespecimenshape.Forferritematerialsshowingthisbehavior,itisusefultocharacterizetheabsorptionbymeansofaneffectivegyromagneticratioandaresonancelinewidth.NotethatferritematerialsexistforwhichtheabsorptionhasamorecomplexbehaviorasafunctionofDCmagneticfield;thismethodisnotintendedtoapplytosuchmaterials.2.2Thevalueofthefieldformaximumabsorptionorresonancemaybecomputedintermsofthemagnetizationofthesample,itsgeometry,theeffectivegyromagneticratio,g,andthetestfrequency.Forthec...
