Absorption properties of geopolymer from fly ash (FA) as a matrix, graphite and nickel or graphite and iron powder as a filler have been carried out by applying Cs-137 gamma ray source. Composite geopolymer was produced by the activating an alkaline solution and heated at 70 °C for 1 h. The optical phonon vibration determined from the quantitative analysis of Fourier transform infra-red (FTIR) spectra by using Krames Kronig (KK) relations. The difference between two optical phonon mode (LO-TO), longitudinal optical (LO) and transversal optical (TO) provided information of the stability bonding formation structure of composite geopolymer, for A-2 (graphite and nickel as a filler) shows the difference is 192 cm and for A-3 (graphite and iron as a filler) shows the difference is 222 cm. The higher differences of optical phonon vibration mode is more stable bonding connection in composite compared with the lower differences. The TO mode was confirmed by the main peak position of imaginary dielectric function (ε). The higher wavelength peak position of the LO for A-3 which confirmed by the energy loss function (ELF) (Im (−1/ε) compared with the A-2 due to the large of atomic radius of Fe (1.56 Å) compared with Ni (1.49 Å). The plasma frequency identified from the ELF is 1600 cm for A-2 and 1757 cm for A-3. The absorption properties of sample A-3 by the attenuation coefficient 0.174 ± 0.008 cm is higher and more effective than the sample A-2. The existence of large empty space on the sample A-2 is evidenced by its value of MFP which is higher than the sample A-3. In this study shows that the higher differences of two optical phonon vibration mode strongly influenced to the absorption properties which shows A-3 (graphite and iron) more effective than the A-2 (graphite and nickel) as a shield due to the strong bonding connection Al–Fe–Si formed in composite geopolymer.

中文翻译：

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粉煤灰-金属复合地质聚合物光学声子振动及伽马射线屏蔽性能研究


应用Cs-137伽马射线源对以粉煤灰（FA）为基体、石墨和镍或石墨和铁粉为填料的地质聚合物的吸收性能进行了研究。通过活化碱性溶液并在 70°C 下加热 1 小时来生产复合地质聚合物。使用 Krames Kronig (KK) 关系通过傅里叶变换红外 (FTIR) 光谱的定量分析确定光学声子振动。两种光学声子模式（LO-TO）、纵向光学（LO）和横向光学（TO）之间的差异提供了复合地质聚合物的稳定性键合形成结构的信息，对于A-2（石墨和镍作为填料）显示了差异为 192 厘米，对于 A-3（石墨和铁作为填料）显示差异为 222 厘米。光学声子振动模式差异越大，复合材料中的键合连接越稳定。 TO 模式由虚介电函数 (ε) 的主峰位置确定。由于 Fe 的原子半径较大 (1.56 Å)，与 A-2 相比，A-3 的 LO 的波长峰值位置更高，通过能量损失函数 (ELF) (Im (−1/ε) 证实）由 ELF 确定的 A-2 的等离子体频率为 1600 cm，A-3 的吸收特性为 1757 cm，衰减系数为 0.174 ± 0.008 cm。样品A-2的MFP值高于样品A-3，证明了样品A-2上存在较大的空白空间。 本研究表明，两种光学声子振动模式的较大差异对吸收特性产生强烈影响，这表明由于强结合，A-3（石墨和铁）作为屏蔽比 A-2（石墨和镍）更有效在复合地质聚合物中形成 Al-Fe-Si 连接。