## 3 State-of-the-Art of YIG  
Yttrium iron garnet (Y\({}_{3}\)Fe\({}_{5}\)O\({}_{12}\), YIG) is a versatile ferromagnetic insulator with low magnetic damping and outstanding magneto-optical characteristic that has been widely utilized in electrical and microwave devices, including oscillators, filters, antennas, phase shifters, and magnetic field sensors [59]. In 1957, the first publication of YIG [60] was published. [PERSON] and [PERSON]'s publication [60] garnered 250 citations. In their study, the crystal structure and ferrimagnetism of YIG are described. The distance between tetrahedral iron and oxygen is 1.88 A, the distance between octahedral iron and oxygen is 2.00 A, and the lengths between yttrium and oxygen are 2.37 A and 2.43 A. Interionic lengths and angles are essential for magnetic ion interaction. Fe\({}^{3+}\) in the 16(a) and 24(d) places had the strongest magnetic interactions. Figure 2 depicts the crystal structure of YIG as described by [PERSON] and [PERSON] in their publication [60]. YIG exhibits a cubic symmetry, defined composition, trivalent metal ions, large Faraday constant, and minimal magnetic damping. These qualities make it ideal for studying spin-waves, magneto-optical phenomena, and magnetic insulator-based spintronics [9]. YIG films and films of other iron garnets were the topics of intensive research. Perspectives for the development of a variety of microwave filters, delay lines, and magneto-optical devices for information storage and processing, such as magneto-optical transparencies, displays, deflectors, optical insulators, read heads, and integrated magneto-optical devices, have sparked interest in these films. The use of YIG in these investigations was necessitated by the material's superior magnetic, optical, and magneto-optical properties, including incredibly low spin-wave damping, great transparency in a broad spectrum range, and a strong Faraday effect [61]. There has also been a growing interest in the production of metamaterials having simultaneously negative permittivity and permeability, known as double negative materials (DNMs), exhibiting \"reversed\" electromagnetic properties and innovative potential applications [59; 62; 63; 64]. Because of its superior negative permeability features, YIG is the most promising candidate for the realization of negative permeability [65]. YIG can generate negative permeability in the absence of an external magnetic field. When a magnetic field is provided, the negative permeability of YIG can become adjustable [66]. With YIG's potential for use in the construction of metamaterials, its magnetic properties had been exhaustively investigated to tune for either negative permittivity or negative permeability [59; 65; 66]. This is significant, as ferrimagnetic YIG with simultaneously negative permittivity and negative permeability have excellent metamaterial performance and become an effective alternative for ordered metamaterials in wave-transparent, solar energy harvesting fields and microwave-absorbing [64]. In recent years, magnetic heterostructures with nanoscale YIG layers have gained popularity. The latest innovations in magnonics and oxide spintronics have sparked interest in transporting information via spin-wave packets instead of current carriers [61]. Using the Scopus database, only papers published between 2012 and 2020 were listed among the top articles. The dataset covers 100 of the most cited papers from 2012 to 2020, as shown in Table 1. The data are organized in Table 1 according to rank, author name, publication year, number of authors, journal, publisher, impact factor, country, and research methodology. Impact factor values for the most recent year of article publication have been determined. According to the findings in Table 1, the number of publications annually produced in the YIG field has varied throughout the period. The data from Table 1 will be statistically and graphically analyzed using VOS viewer, Microsoft Excel, and Microsoft PowerPoint software. The gathered information is described in Section 4.