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

課題番号 Project No. 2014A0330

装置責任者 Name of responsible person

実験課題名 Title of experimentToshiya Otomo

Structure analysis for amorphous carbon with low friction by

装置名 Name of Instrument/（BL No.）

total scattering measurement

NOVA/BL21

実験責任者名 Name of principal investigator

実施日 Date of Experiment

Hiroshi NOZAKI

2014/6/13-13, 11/20-21

所属 Affiliation
Toyota Central R&D Labs., Inc.
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.
DLC1: CDa, DLC2: CDb, DLC3: CDc, DLC4: CDd (a,b,c,d = 0.1 ~ 0.4), DLC5: synthetic graphite (C).

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.

1. Experimental
The samples of amorphous carbon (CDx: DLC) were synthesized on an iron plate by a plasma chemical vapor
deposition (CVD) method using CD4 gas as a precursor. We used CD4 gas instead of CH4 gas because hydrogenproduces a large background in a neutron scattering spectrum. Then, the powder sample was collected byscratching the deposited DLC [1].
graphite as a reference sample.

We produced four DLC samples with different C/D ratio and synthetic

The powder samples were filled into a vanadium container in air.

The neutron

scattering spectra S(Q) was measured on NOVA spectrometer at room temperature for several hours. Then, theradial distribution function (RDF) spectra were obtained by a Fourier transform.

12. 実験方法及び結果（つづき） Experimental method and results (continued)
The RDF spectra are shown in Fig. 1. There areclear several peaks (rn; i=1-7) corresponding to the
C-C, C-D, or D-D bonds at r < 5Å region for eachsample. Because the peak position of r2 (=1.41 Å), r4(=2.44 Å), r5 (=2.88 Å), r6 (=3.69 Å), r7 (=4.25 Å) for
DLC are same as synthetic graphite, those peaks arethought to be derived from C-C bond. From thestructural analysis, r2, r4, and r5 correspond to thenearest-neighboring (NN) C-C bond, the next NN C-Cbond, the third NN C-C bond within the ab-plane,
respectively. r6, and r7 correspond to the shortest andthe second shortest C-C distance between theinter-layer of graphene, respectively. On the otherhand, r1 (=1.1 Å) and r3 (=2.1 Å) corresponds to thedirect C-D bond and the C-D distance between the Datom of C-D bond and the C atom adjacent C-D bond(see Fig. 2). From the peak intensity of r1, the amountFig.1 RDF spectra for four DLC samples andof D atom for each sample is considered to be thereference. Each spectra shifted vertically for thefollowing order; DLC3 ~ DLC4 < DLC1 < DLC2.

clarity.

Here, because the statistics for DLC4 sample arerelatively low due to the less amount of powder, theamount of DLC4 may be less than DLC1. This isprobably connected to the cluster size; that is, thelarger the size of cluster is, the less the D/C ratio is.
[references][1] T. Iseki, et al., Diamond and Related Materials 15,1004 (2006).

Fig.2 The planer structure of graphene.
Black and red solid-line show C-C bondand C-D bond, respectively.

2