[14p-C41-1~21] 10.4 Semiconductors, organic, optical, and quantum spintronics

△ [14p-C41-20] Manipulation of the magnetic properties of lepidocrocite layered titanates by controlling distances between dopant Co and Fe ions

〇(D)Fuminao Kishimoto¹, Yota Takamura¹, Shigeki Nakagawa¹, Yuji Wada¹ (1.Tokyo Inst. Tech.)

Keywords:Layered compound, Doping, Nanostructure

We demonstrated that the magnetic property of n-alkylamine intercalated ferromagnetic 3d transition metal doped layered titanate (Ti_(5.2-x)/3Li_(0.8-2x)/3Co_xO₄ (x=1,3,4) and Ti_1.5Fe_0.2Co_0.3O₄) can be manipulated by controlling the interlayer distance which is controlled from 0.7 nm to ~3 nm by changing the carbon chain length of interlayer n-alkylammonium. The maximum magnetic moment (at 20 kOe) of Ti_(5.2-x)/3Li_(0.8-2x)/3Co_xO₄ (x=1,3,4) is increased continuously in association with the expansion of the interlayer space. This tendency is observed more strongly in the dilute doped layered materials. This result can be explained as resulting from the edge effect caused by surface expose of Co atoms, and from the quantum confinement in the discrete nanolayer. On the other hands, the maximum magnetic moment (at 20 kOe) of Ti_1.5Fe_0.2Co_0.3O₄ is decreased with the expansion of the interlayer space. This decrement can be attributed to distance-dependent exchange interaction at the between the layers.