Magnesiumoxide(MgO)nanowiresweresynthesizedonthegold-coatedSi(100)andMgO(100)substratesatlowertemperature(600℃)bypulsedliquidinjectionmetalorganicchemicalvapordeposition(MOCVD).Thegoldcatalystcouldbefoundonthetipsofnanowires,whichpresentsthevapor-liquid-solid(VLS)growthmechanism.Reactivespecies(oxygenormagnesium)havestrongeffectsonthegrowthofnanowires.Abundantreactivespecieskilltheverticallyalignednanowirestoberandomlyalignedonesorevenchangetheverticalgrowthmodetothehorizontalgrowthmodewithsurface-parallelnanowires.Usually,nanowireswithlargeraspectratio(>10,aspectratio=length/diameter),higherdensity(>500/μm2)andsmallerdiameter(≤20nm)canbeeasilysynthesizedwithlongerinjectionperiod(≥2s),smallerinjectionmass/period(≤4.6mg)andsuitableoxygenpartialpressure(2.4Torr).
