Thermionic emission behaviors of lanthanum hexaboride coated W/Mo/Ta wires

An Erratum to this article was published on December 29, 2023. https://dergipark.org.tr/en/pub/boron/article/1371867

Abstract

Among the hexaborides, lanthanum hexaboride (LaB6) stands out thanks to its unique properties such as low operating function between 2.4 eV and 2.9 eV, high melting temperature, high chemical stability and low evaporation temperature. It is aimed to produce LaB6 cathodes, which are used as electron sources in electron microscopes, as thin film filaments by using magnetron sputtering (MS) system. La-hexaboride film was coated on tungsten (W), molybdenum (Mo), tantalum (Ta) wires used as substrate by using magnetron sputtering system and their physical, chemical, microstructural properties were analyzed. Before coating the lanthanum hexaboride, a carbon coating in the form of graphite was applied as a diffusion barrier to form a diffusion barrier between the substrate and the target material. Thermionic emission behavior of the coated films was analyzed.

Keywords

• Electron emission
• Lanthanum hexaboride filament
• magnetron sputtering system
• thermionic coatings

Lantan hekzaborür kaplanan W/Mo/Ta tellerin termiyonik emisyon davranışları

An Erratum to this article was published on December 29, 2023. https://dergipark.org.tr/en/pub/boron/article/1371867

Abstract

Hekzaborürler arasında lantan hekzaborür (LaB6) 2.4 eV ile 2.9eV arasındaki düşük çalşma fonksiyonu, yüksek erime sıcaklığı, yüksek kimyasal stabilitesi ve düşük buharlaşma sıcaklığı gibi eşsiz özellikleri sayesinde öne çıkmaktadır. Elektron mikroskoplarında elektron kaynağı olarak kullanılan LaB6 katotların magnetron sıçratma (MS) sistemi kullanılarak ince film filament olarak üretilmesi hedeflenmektedir. Alttaş olarak kullanılan tungsten (W), molibden (Mo), tantal (Ta) tellerin üzerine magnetron sıçratma sistemi kullanılarak La-hekzabörür film kaplanılmıştır ve fiziksel, kimyasal ve mikroyapı özelliklerinin analizleri yapılarak incelenmiştir. Lantan hekzaborür kaplanmadan önce difüzyon bariyeri olarak grafit formunda karbon kaplaması yapılarak alttaş ile hedef malzeme arasında difüzyon bariyer oluşturulmuştur. Kaplanan filmlerin termiyonik emisyon davranışlarının analizi yapılmıştır.

Keywords

• Elektron Emisyonu
• Lantan Hekzaborür filament
• Magnetron sıçratma sistemi
• Termiyonik Kaplamalar

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