Fe₃O₄ 나노입자는 hot-injection 제조법에 의해 제조되었으며 반응물질의 injection time에 변화를 주었다. 격자구조는 x-ray diffraction(XRD) 측정을 통해 Fd-3m 공간군을 갖는 cubic inverse spinel 구조로 분석되었으며, Fe₃O₄ 나노입자의 형상은 high-resolution transmission electron microscope(HR-TEM)으로 분석하였다. 반응물질을 각각 0.5분, 60분인 젝션시 각각 7.63 nm, 21.73 nm의 Fe₃O₄ 나노입자 사이즈를 얻을 수 있었다. Fe₃O₄ 나노입자의 자기적 특성은 다양한 온도에서 vibrating sample magnetometer(VSM)과 Mössbauer spectroscopy로 측정하였으며, hyperthermia 측정을 통해 반응 물질의 injection time이 60분일 때 50 kHz의 250 Oe에서 Fe₃O₄ 나노입자 파우더의 온도가 약 120 ^oC임을 관측할 수 있었다.

The Fe₃O₄ nanoparticle was synthesized by the hot-injection method while varying the injection time of the precursor solution. The crystal structure was determined to be cubic inverse spinel with space group of Fd-3m based on X-ray diffraction (XRD) measurements and the morphology of the prepared Fe₃O₄ nanoparticle was studied with a high-resolution transmission electron microscope (HR-TEM). When the precursor solution was injected for 0.5 min, the size of the Fe₃O₄ nanoparticle was 7.63 nm, while the size of the obtained particle was 21.27 nm with the injection time of 60 min. The magnetic properties of the prepared Fe₃O₄ nanoparticle were investigated by both vibrating sample magnetometer (VSM) and ⁵⁷Co Mössbauer spectroscopy at various temperatures. From the hyperthermia measurement, we observed that the temperature of the Fe₃O₄ nanoparticle powder reached around 120 ^oC under 250 Oe at 50 kHz, when the injection time of the precursor solution was 60 min.