## 2 Data Source and Surveying Methodology
### Selection Method  
The technique for performing this study was determined through a top-down review of the top 100 papers in the Scopus database. Certain criteria for selecting highly cited papers from the 100 publications were established based on the following: chosen keywords (yttrium iron garnet, thin film, magnetic properties), publication years (2012-2022), subject area (physics and astronomy, materials science), document type (article), source type (journal), language (English), and relevance and significance to practical topics. The review of evaluating survey methods in the Scopus database is shown as follows:  
1. Evaluation Selection method * During the initial search (first step) of the Scopus database, a total of 5429 papers on yttrium iron garnet were discovered. Due to the large number of papers, the sample size was too large for an exhaustive search and analysis. As a consequence, the articles were chosen and filtered based on a variety of criteria to define the data search. * In Step 2, 1428 papers were identified using the keywords \"thin film\" and \"magnetic properties\". * In Step 3, 896 papers were discovered between the years 2012 and 2022 in the specified subject areas of physics, astronomy, and materials science. * In Step 4, 799 papers were chosen based on the journal source type, article document type, and English proficiency, considering that English is the international language spoken at the United Nations and at majority of international conferences. * In Step 5, 100 papers were identified for final analysis based on their title, abstract, content relevancy, and contribution to practical topics. All shortlisted publications were the research published in international journals between 2012 and 2022. The papers were sorted from highest to lowest by citation count. The data obtained from the 100 scholarly papers on YIG constitute a sufficient evaluation of the literature on the topic.  
The 100 articles chosen to explore a wide range of topics: (a) state-of-the-art discussion of the top articles with the highest citation counts; (b) publishing performance and trends (include citation structure and the countries involved and leading the research areas); (c) top 10 articles evaluation; (d) subject categories evaluation; (e) evaluation techniques based on methodologies, substrate types, and film characterization and applications; (f) favorable keyword evaluations; and (g) document evaluations, which may contain journal articles and their impact factors. For future directions, applications of YIG-based literature, difficulties, and recommendations were described.  
2. Review discussions and findings * Data sources and surveying methodology include selection method and yearly trends in scientific publications. * State-of-the-art YIG based on the top 10 articles were discussed, including the methodologies, scope, findings, and research gaps. * The analytical discussion concentrated on publication performance and trends, subject categories and evaluation, methodological journal evaluation, keyword assessment, document type evaluation, and evaluation of the most prominent authors. * Future directions and conclusions emphasize the applications, challenges, and solutions underlying YIG. General recommendations for promoting YIG research were provided.