The present invention relates to a heat-generating composition, comprising a hetero-structure nanomaterial which comprises (a) a first material comprising at least one component selected from the group consisting of a metal, a metal chalcogen, a metal pnicogen, an alloy and a multi-component hybrid structure thereof； and (b) a second material comprising at least one component selected from the group consisting of metal, metal chalcogen, metal pnicogen, alloy and the multi-component hybrid structure thereof； wherein the first material is enclosed in the second material； wherein at least one of the first material and the second material comprise a magnetic material. The specific loss power of the present nanomaterial is much higher than that of conventional nanomaterials (e.g., 40-fold higher than commercially accessible Feridex) and may be controlled by changing compositions or ratios of the first material and/or the second material. The heat-generating nanomaterial of the present invention may be used in a variety of application fields, for example cancer hyperthermia.
