2023
<2> Nanoscale Etching of La0.7Sr0.3MnO3 Without Etch Lag Using Chlorine Based Inductively Coupled Plasma
Nimphy Sarkar, Jaewoo Han, Daryll Joseph Chavez Dalayoan, Satyabrat Behera, Sang-Hyuk Lee, Cheng Chen, Dai-Sik Kim, Changhee Sohn & Seon Namgung
Electronic Materials Letters (2023)
Abstract: La0.7Sr0.3MnO3 (LSMO) has been considered as a promising material for future electronic and spintronic device application due to its unique properties such as pure spin polarization, colossal magnetoresistance, and high temperature coefficient of resistance (TCR). To apply this promising material for practical application, large epitaxial LSMO layers should be etched into micro- and nano-scale device structures. However, a comprehensive study on the etch of LSMO has not been demonstrated yet. Herein, the etch rates of LSMO are studied using inductively coupled plasma reactive ion etching (ICP-RIE) method, while controlling critical etching parameters such as ICP source power, radio frequency (rf) chuck power, etching gas ratio, and chamber pressure. We found that the etching process can be applied to nanoscale structures (down to 100 nm) without etch lag effect, exhibiting smaller etch depth in smaller features. This study will provide a good reference for the etching and the engineering of LSMO toward future electronic and spintronic devices such as highly sensitive bolometers and low-power memory devices.
Zhihao Wang, Yingde Zhang, Cheng Chen, Hong-Guang Piao, Linjie Ding, Liqing Pan, Jiaohong Huang, Hyeong-Ryoel Park, Dai-Sik Kim, Seong-Cho Yu
Journal of Magnetism and Magnetic Materials 565, 170147 (2023)
Abstract: For the widespread application of solid magnetic refrigeration technology, this is one of the key technologies to realize the wide temperature range of magnetic entropy change near room temperature. In this paper, the effect of Ni-doping on the magnetocaloric properties and the temperature range of magnetic entropy change was studied for La(Fe0.94−xNixCo0.06)11.4Si1.6B0.25 alloy subjected to the industrial high-frequency suspension furnace. The results show that the Curie temperature of the alloy system can be adjusted to room temperature by changing the Ni content, and the temperature range of magnetic entropy change can be expanded effectively. In addition, the critical behavior of the industrial grade purity alloy system was evaluated by modified Arrott-plot and critical isotherm analysis methods, and the optimal values of critical parameters were obtained, providing a novel thermodynamic method to determine the critical behavior of magnetic phase transition in La(FeSi)13 alloy system.