Investigation of New Soft Magnetic Films for GHz Magnetic Recording Heads and Integrated Inductors

低矫顽力和高磁导率的软磁薄膜是许多电磁设备的重要组成部分，如磁记录磁头、集成电感(微电感)、集成变压器、磁传感器和微机械电机。然而，缺乏具有高饱和磁化强度(20 Kg)、大磁导率(1000)和大铁磁共振频率(1 GHz)的软磁材料往往是这些应用的瓶颈。例如，到2003年，硬盘驱动器的数据率预计将达到~1 GB/S(1 GB=10亿比特)。2 Gb/S的数据速率相当于~1 GHz的记录频率，超过了大多数磁性材料的铁磁共振频率。因此，研究能够以1 GHz的频率进行磁记录的新材料、磁化动力学和记录物理变得越来越迫切。在本项目中，我们提出了以下建议：1)研究一种新的软磁材料，即饱和磁化强度为~24 kg的Fe-Co-N薄膜(FeCoN)，它将使硬盘驱动器具有更高的面记录密度(每平方英寸100 GB)。2)研究1 GHz的磁化动力学和磁记录，如果简化到实践中，这是一个重要的里程碑。3)评估用于集成电感的新型Fecon材料的可行性，这是便携式无线通信设备等新兴应用所需的。4)通过博士论文研究、本科生研究体验、课堂教学等方式对研究生和本科生进行信息存储技术教育。

Soft magnetic films with low coercivity and high permeability are critical building blocks in numerous electromagnetic devices such as magnetic recording heads, integrated inductors (microinductors), integrated transformers, magnetic sensors, and micromachined motors. However, a lack of soft magnetic materials with a high saturation magnetization (20 kG), a large permeability (1000), and a large ferromagnetic resonance frequency (1 GHz), tends to be the bottleneck in these applications. For example, the data rate of hard disk drives is expected to be ~1 Gb/s (1 Gb = 1 billion bits) by year 2003. A data rate of 2 Gb/s corresponds to a recording frequencies of ~1 GHz, which exceeds the ferromagnetic resonance (FMR) frequency of most magnetic materials. Therefore, it is increasingly urgent to investigate new materials, magnetization dynamics, and recording physics which will enable magnetic recording at a frequency of 1 GHz. In this project, we propose the following: 1) Investigate a new soft magnetic material, namely Fe-Co-N films (FeCoN) with a saturation magnetization of ~24 kG, which will enable higher areal recording densities in hard disk drives (100 Gb per square inch). 2) Study magnetization dynamics and magnetic recording at 1 GHz, an important milestone if reduced to practice. 3) Evaluate the viability of the new FeCoN material for integrated inductors, which are desired for emerging applications such as portable wireless communication devices. 4) Educate graduate students and undergraduates about information storage technology via doctoral thesis research, research experience for under graduate (REU), and classroom teaching.