実験報告書様式（一般利用課題・成果公開利用）（ ※本報告書は英語で記述してください。ただし、産業利用課題として採択されている方は日本語で記述していただいても結構です。 ）MLF Experimental Report

提出日 Date of Report
2011/06/30

課題番号 Project No.

装置責任者 Name of responsible person

2010B0040

Norifumi Yamada

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

BL16 High-Perfomance Neutron Reflectometer with a Hozizontal

BL16Sample Geometery

Reflectometer with a Hozizontal Sample

実験責任者名 Name of principal investigator

Geometery

Masao Yonemura

実施日 Date of Experiment

所属 Affiliation

2011/03/08-2011/03/11

High-PerfomanceNeutronHigh Energy Accelarator Research Organization, Institute ofMaterials Structure Science
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
Li3PO4(approx. 3nm)/Li4Ti5O12(approx. 23nm)/STO111(Substrate)

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

Epitaxial Li4Ti5O12(LTO) thin films modified by Li3PO4(LPO) at the surface were synthesized on the plane(111) of a 0.5% Nb-doped SrTiO3 substrate by pulsed laser deposition using a KrF excimer laser with awavelength of 248nm and pulsed laser deposition system (PLAD131, AOV inc). The synthesis condition isskipped. An in-situ spectroelectrochemical cell designed for Neutron Reflectivity measurements provided
continuous surface changes with electrochemical lithium intercalation and de-intercalation. An electrolyte
solution of ethylene carbonate and propylene carbonate with a molar ratio of 1:1 and 1M –LiClO4 was injected
into the cell.

De-intercalation and intercalation were performed by the potentiostatic method withpotentiostat/galvanostat (Invium Tech., Compactstat). Structural changes were observed by thepotentiostatic method during electrochemical (de)intercalation. The reflectivity was measured as a function of
the momentum transfer in a Q range of 0.07 to approx. 0.15Å-1.
At 2010A period, the only LTO thin films were measured and observed concentration gradient at theelectrolyte solution side. To investigate the more detail of structure changes at electrolyte solution, LTO thinfilms modified by LPO were measured. The concentration gradient was formed by the interaction between theelectrode and electrolyte solution and that the modification by LPO will affect the electrolyte side structurechanges.
12. 実験方法及び結果（つづき） Experimental method and results (continued)
Fig. 1 shows the results of in-situ neutron reflectivity measurements. Reflectivity data obtained during theelectrochemical process were analyzed, but that is still not enough. The obtained value of scattering lengthdensity of LTO is 3.8x10-6. This is rather largeｒ than Li4Ti5O12’s one, 2.1x10-6. The non-modified LTO shows
the scattering length density is 2.2x10-6, thus there is a possibility that the LPO affect properties of the bulk
LTO. The interfacial structures are not clear. We carry forward the analysis with the other method, X-ray
reflectivity and so on.

Fig.1 In-situ neutron reflectivity spectra of LTO thin
films

modifiedbyLPO

duringcharge/dis-chargeing ondictions.

2thefirst