Acquisition of a Superconducting Magnetooptical Cryostat for Research and Student Training in Magnetoelectronic Materials

这是DMR材料研究项目仪器的一个奖项，授予学院和威廉和玛丽。该奖项是为了获得7特斯拉超导磁光低温恒温器，用于研究铁磁薄膜多层膜中的非线性磁光效应和磁输运。这种多层膜在技术应用中显示出巨大的前景，但受限于对电子自旋寿命和自旋散射和自旋翻转的来源的不完全了解。该设备将被纳入一个超快泵浦-探测激光光谱系统，包括频率相关和时间分辨的磁光克尔效应和磁化诱导二次谐波产生，以回答有关自旋极化以及自旋和磁化动力学的问题。该仪器还将用于培训该学院的学生学习磁电子学的重要材料。%该奖项从材料研究仪器威廉和玛丽学院是为收购低温，高场磁光低温恒温器，这将加强研究和教育领域的磁光和磁输运在学院。低温恒温器将被纳入一个系统，该系统使用超快脉冲激光技术（激光脉冲持续时间小于万亿分之一秒）来测量薄膜铁磁多层膜的磁特性如何随时间演变。在这些技术中，“泵浦”光束被用来激发所研究的材料，而第二脉冲光束“探测”，或在稍后的时间拍摄系统状态的快照。例如，这种技术已经成功地用于研究化学反应，直到最近才被应用于磁性材料。研究磁性过程的极限速度以及决定磁性薄膜的磁和电特性的因素对于电子和磁性设备的设计非常重要，例如硬盘读取头，非易失性计算机存储器和基于电子自旋的下一代计算机设备（称为“自旋电子学”或“磁电子学”）。

This is an award from the Instrumentation for Materials Research program in DMR to the College and William and Mary. The award is for acquisition of a 7 Tesla superconducting magnetooptical cryostat for the study of nonlinear magnetooptical effects and magnetotransport in ferromagnetic thin film multilayers. Such multilayers are showing great promise in technological applications, but are limited by incomplete knowledge of electron spin lifetimes and the sources of spin scattering and spin-flipping. This equipment will be incorporated into a system for ultrafast pump-probe laser spectroscopy, including frequency-dependent and time-resolved magneto-optical Kerr effect and magnetization-induced second harmonic generation, to answer questions regarding spin polarization and spin and magnetization dynamics. The instrument will also be used in training of students at the College to study materials important for magnetoelectronics. %%%This award from the Instruments for Materials Research to the College of William and Mary is for the acquisition of a low-temperature, high-field magnetooptical cryostat which will enhance research and education in the areas of magnetooptics and magnetotransport at the College. The cryostat will be incorporated into a system which uses ultrafast pulsed laser techniques (with laser pulses less than one-trillionth of a second in duration) to measure how the magnetic properties of thin-film ferromagnetic multilayers evolve in time. In these techniques, a "pump" beam is used to excite the material under study while a second pulsed beam "probes", or takes a snapshot of the state of the system later in time. Such techniques have been successfully used, for example, to study chemical reactions as they occur, and have only recently been applied to magnetic materials. The study of the ultimate speed of magnetic processes and what determines the magnetic and electrical properties of magnetic thin films is extremely important for the design of electronic and magnetic devices such as hard drive read heads, nonvolatile computer memory and the next generation computer devices based on electron spin (dubbed "Spintronics" or Magnetoelectronics").