Bazı nadir toprak elementleri borür bileşiklerinin sentezi
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Dosyalar
Tarih
2021
Yazarlar
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Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, açık havada magnezyotermik indirgeme ile mikro ve nano boyutta PrB6, DyB6 ve YbB6 sentezlendi ve bu maddelerin eldeleri için gerekli optimum reaksiyon koşulları tespit edildi. Ham madde olarak Pr6O11, Dy2O3, Yb2O3, B2O3 ve indirgen madde olarak Mg kullanıldı. Optimum (en çok verimin alındığı) sıcaklığı belirlemek için, reaksiyon süresi sabit tutularak (2 saat) 600, 700, 800 ve 900 °C'de tepkime vermeleri sağlandı. Optimum sıcaklık PrB6 ve YbB6 için 900 °C, DyB6 için 800 °C olarak saptandı. Daha sonra maddeler için optimum olan sıcaklıklarda(800, 900 °C) sabit tutularak 4, 8, 12, 16, 20 saat süreyle tepkime vermeleri sağlandı. En uygun tepkime süresi PrB6 için 8 saat, DyB6 ve YbB6 için 4 saat olduğu tespit edildi. Oluşan bileşikler X-Işını Kırınımı (XRD), Taramalı Elektron Mikroskobu (SEM) ve Enerji Dispersif Spektrometri (EDS) ile analiz edildi. XRD analizi ile saf PrB6, DyB6 ve YbB6 oluştuğu XRD ile kanıtlandı. Numunelerin morfolojilerini karakterize etmek için SEM analizi yapıldı. Heterojen ve nano–mikro boyutta PrB6, DyB6 ve YbB6 varlığı gözlendi. Sentezlenen maddelerin Gama ışını zırhlama etkisi, Monte Carlo(MC) yöntemi ile araştırıldı. EGSnrc kodu kullanılarak gama ışını zırhlama parametreleri; kütle zayıflama katsayıları, yarı değer kalınlığı, onuncu değer kalınlığı, ortalama serbest yol, etkin atom numarası, etkin elektron yoğunluğu, toplam atom kesit ve toplam elektronik kesit belirlendi Nist'in XCom programı ile hesaplanan sonuçlarla karşılaştırıldı. MC ve XCom arasında hesaplanan sonuçlar başarılı bir tutarlılık gösterdi. Elde edilen sonuçlar, standart radyasyon koruyucu malzeme olarak bilinen saf kurşunla da karşılaştırıldı. Üretilen hekzaborürlerin, literatürde daha önce incelenen malzemelere kıyasla en umut verici gama koruma özelliklerine sahip olduğu sonucuna varıldı.
In this study, micro and nano-sized PrB6, DyB6 and YbB6 were synthesized by magnesiumothermic reduction in open air, and the optimum reaction conditions for obtaining these substances were determined. Pr6O11, Dy2O3, Yb2O3, B2O3 were used as raw materials and Mg was used as reducing material. In order to determine the optimum and most efficient temperature, the reaction time was kept constant (2 hours) and they were allowed to react at 600, 700, 800 and 900 °C. The optimum temperature was 900 °C for PrB6 and YbB6, and 800 °C for DyB6. Then they were allowed to react for 4, 8, 12, 16, 20 hours by keeping them constant at the optimum temperatures (800, 900 °C). The optimum reaction time was 8 hours for PrB6 and 4 hours for DyB6 and YbB6. The resulting compounds were analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDS). Pure PrB6, DyB6 and YbB6 were proved by XRD analysis. SEM analysis was performed to characterize the morphology of the samples. Heterogeneous and nano-micro size PrB6, DyB6 and YbB6 presence was observed. Gamma ray screening effect of synthesized substances was investigated by Monte Carlo (MC) method. Gamma ray protection parameters using the EGSnrc code; mass attenuation coefficients, half value layer, tenth value layer, non-average path, effective atomic number, effective electron density, total atomic cross section and total electronic cross section were determined and compared with the results calculated by Nist's XCom program. Calculated results between MC and XCom showed good consistency. The results obtained were also compared with pure lead, known as the standard radiation shielding material. It was concluded that the hexaborides produced had the most promising gamma protection properties compared to materials previously studied in the literature.
In this study, micro and nano-sized PrB6, DyB6 and YbB6 were synthesized by magnesiumothermic reduction in open air, and the optimum reaction conditions for obtaining these substances were determined. Pr6O11, Dy2O3, Yb2O3, B2O3 were used as raw materials and Mg was used as reducing material. In order to determine the optimum and most efficient temperature, the reaction time was kept constant (2 hours) and they were allowed to react at 600, 700, 800 and 900 °C. The optimum temperature was 900 °C for PrB6 and YbB6, and 800 °C for DyB6. Then they were allowed to react for 4, 8, 12, 16, 20 hours by keeping them constant at the optimum temperatures (800, 900 °C). The optimum reaction time was 8 hours for PrB6 and 4 hours for DyB6 and YbB6. The resulting compounds were analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDS). Pure PrB6, DyB6 and YbB6 were proved by XRD analysis. SEM analysis was performed to characterize the morphology of the samples. Heterogeneous and nano-micro size PrB6, DyB6 and YbB6 presence was observed. Gamma ray screening effect of synthesized substances was investigated by Monte Carlo (MC) method. Gamma ray protection parameters using the EGSnrc code; mass attenuation coefficients, half value layer, tenth value layer, non-average path, effective atomic number, effective electron density, total atomic cross section and total electronic cross section were determined and compared with the results calculated by Nist's XCom program. Calculated results between MC and XCom showed good consistency. The results obtained were also compared with pure lead, known as the standard radiation shielding material. It was concluded that the hexaborides produced had the most promising gamma protection properties compared to materials previously studied in the literature.
Açıklama
Anahtar Kelimeler
Kimya, Chemistry
