In order to realize spin caloritronics, a ferrimagnet insulator-Y3Fe5O12 (YIG) has been intensively studied due to its excellent magnonic properties such as a low attenuation and long wavelength. Most of studies has been performed on the single-crystalline YIG thin film because it has been known that a single-crystal YIG has high magnetic and magnonic properties. However, the fabrication of single-crystalline YIG is too difficult to apply practically. In this study, we propose a fabricating method for bulk-YIG using the sol-gel synthesis, a conventional as well as commercial method for metal oxide materials. To enhance magnetic properties of the sol-gel-synthesized bulk-YIG, we optimized an external mechanical pressure process and heat treatments. The calcination process was carried out at 850 °C in the air at the ratio of 7.0 °C/min to get rid of the crystallization and residual impurities. After calcined, pressing was progressed under the 15 MPa for 5 minutes to fabricate bulk- and thin-YIG. Finally, the sintering has been done at 1400 °C at the ratio 5.0 °C/min. Magnetic properties were measured using vibration sample magnetometer at 300 K in case of the different states; powder and fillet. From the x-ray diffraction measurements, we found that the crystalline structure was formed after the calcination process. Our optimized pressing and sintering process significantly improves the saturation magnetization (Ms) of the sol-gel-synthesized bulk-YIG. A huge enhancement of Ms value might be understood from the completeness of densification after the pressing and sintering process. Our results have paved the way for YIG to be used in real spin caloritronic materials.

Enhancement of magnetic properties of Y3Fe5O12 (YIG) prepared by the sol-gel synthesis with an optimized mechanical pressing process for spin-caloritronic materials

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.