noun
Academic field studying the properties, structure, and applications of materials.
彼は大学で物質科学を専攻している。
He is majoring in materials science at university.
材料科学 is a near-synonym also meaning materials science; 物質科学 may emphasize the fundamental physics and chemistry of materials, while 材料科学 often focuses on engineering applications.
Compound of 物質 (material, substance) and 科学 (science).