## 1 Introduction  
Coatings based on refractory metal silicides are one of the most promising materials for protecting critical parts exposed to high temperatures, aggressive gas environments and various types of wear. High working temperatures pose challenges, as they require materials that are resistant to oxidation and have good mechanical strength and high thermal and phase stability. Among silicide coatings, TaSi\({}_{2}\) has a higher hardness and fracture toughness compared to other coatings such as NbSi\({}_{2}\) and MoSi\({}_{2}\)[1], as well as high corrosion resistance [2]. TaSi\({}_{2}\) coatings have a high thermal stability and oxidation resistance up to 800 \({}^{\circ}\)C; however, above this temperature, the coating is intensively oxidized as a result of the formation of a loose Ta\({}_{3}\)SiO\({}_{y}\) complex oxide [3]. The service properties of TaSi\({}_{2}\) coatings can be improved using alloying by different elements, such as N, C, B, etc. Our early studies have shown that the introduction of nitrogen into TaSi\({}_{2}\) coatings by reactive magnetron sputtering makes it possible to increase the hardness from 10 to 27 GPa, the elastic recovery from 38 to 80%, the adhesion strength from 15 to 31 GPa and the oxidation resistance from 1000 to 1200 \({}^{\circ}\)C of the coatings by suppressing columnar grain growth, and it can lead to the formation of a nanocomposite structure with a high proportion of an amorphous a-Si\({}_{3}\)N\({}_{4}\) phase [4, 5]. It was shown in [6] that Ta-Si-N coatings with a high silicon content of 26 at.% were characterized by oxidation resistance up to 1300 \({}^{\circ}\)C due to the formation of a surface oxide layer consisting mainly of the orthorhombic o-Ta\({}_{2}\)O\({}_{5}\) phase, which has high barrier properties and prevents the penetration of oxygen deep into the coating. To increase tribological characteristics, carbon is introduced into the composition of TaSi\({}_{2}\) coatings, which contributes to the formation of a solid lubricant during friction [7]. Ta-Si-C coatings are characterized by hardness at the level of 25-30 GPa, a low friction coefficient and high wear resistance at temperatures of 25-800 \({}^{\circ}\)C as well as a high thermal stability and oxidation resistance at a temperature of 800 \({}^{\circ}\)C [8]. The introduction of boron into Me-Si-C and Me-Si-N (Me = Ta, Ti) coatings increases oxidation resistance by reducing the viscosity of the a-SiOOx oxide layer and increasing the self-healing effect [9; 10; 11]. The Ta-Si-B-C coating has a high oxidation resistance at a temperature of 1500 \({}^{\circ}\)C and exposure for 400 h due to the formation of a multilayer oxide film with an inner SiO\({}_{2}\) layer and an outer Ta-Si-O [9]. Additionally, oxidation resistance can be increased by introducing zirconium, the oxidation of which forms a dense oxide film containing dispersed particles of ZrO\({}_{2}\) and/or ZrSiO\({}_{4}\), characterized by low oxygen permeability and high thermal stability [12; 13]. Alloying Ta-Si-B-C coatings with zirconium leads to an increase in adhesive and cohesive strength [14; 15]. The samples demonstrate good resistance to oxidation at a temperature of 1500 \({}^{\circ}\)C, which may be due to the formation of a protective oxide layer of ZrO\({}_{2}\)-SiO\({}_{2}\). The Ta-Zr-Si-B-C and Ta-Zr-Si-B-N coatings were developed based on the high oxidation resistance of Ta-Si-B-C coatings [9] and the positive effect of nitrogen and zirconium on the oxidation resistance and thermal stability of silicide coatings [16; 17; 18]. Previously, we have shown that the Ta-Zr-Si-B-C and Ta-Zr-Si-B-N coatings deposited by magnetron sputtering have a hardness of 30 GPa, a low friction coefficient of 0.2, high wear resistance and oxidation resistance at a temperature of 1200 \({}^{\circ}\)C [19; 20; 21].