Vibrating Sample Magnetometer VSM S Foner VSM 29

振动样品磁强计 Vibrating Sample Magnetometer (VSM) 感谢S. Foner

振 动 样 品 磁 强 计 VSM 29 相关参考文献 1. G. W. van Oosterhout, Appl. Sci. Res. , B 6, 101 -104 (1956) 2. S. Foner, Rev. Sci. Instrum. , 27, 548 (1956) 3. S. Foner, Rev. Sci. Instrum. , 30, 548 -557 (1959) 4. S. Foner, Rev. Sci. Instrum. , 45, 1181 (1974) 5. S. Foner, Rev. Sci. Instrum. , 46, 1425 (1975) 6. A. Zieba and S. Foner, Rev. Sci. Instrum. , 53, 1344 (1982) 7. S. Foner, J. Appl. Phys. , 38, 1510 (1967) 8. S. Foner, J. Appl. Phys. , 79, 4740 (1996)

Helmholtz配置： ＝rc • 平行于轴向 + Mathematica作图

Helmholtz配置： ＝rc • 垂直于轴向 + Mathematica作图

锁相放大器 Lock-in Amplifier 39

商品化VSM的灵敏度 Sensitivity ? ! m 2 10 7 emu t 20 min ～ 30 min 蒙人的灵敏度

样品的形状、尺寸、位置 Sample’s Shape, Size, Position

样品与检测线圈的几何尺寸 参考文献 1. U. Ausserlechner, P. Kasperkovitz, and W. Steiner, “Pick-up systems for vibrating sample magnetometers – a theoretical discussion based on magnetic multipole expansions, ” Meas. Sci. Technol. , 5 (1994), 213 -225. 2. A. C. Bruno and P. Costa Ribeiro, “Spatial Fourier calibration method for multichannel SQUID magnetometers, ” Rev. Sci. Instrum. , 62(4) (1991) 10051009. 3. P. Stamenov and J. M. D. Coey, “Sample size, position, and structure effects on magnetization measurements using second-order gradiometer pickup coils, ” Rev. Sci. Instrum. , 77 (2006) 1015106. 4. Quantum Design, “Accuracy of the reported moment: axial and radial sample positioning error, ” Application Note 1500 -010. 5. Quantum Design, “Accuracy of the reported moment: sample shape effects, ” Application Note 1500 -015.

QD Application Note 1500 -010

QD Application Note 1500 -015

VSM@SCM的问题 VSM样品8 1、样品位置：轴向偏移 QD：VSM@SCM系列 QD Application Note 1500 -010 + 二级梯度线圈

VSM@SCM的问题 VSM样品9 1、样品位置：径向偏移 QD：VSM@SCM系列 QD Application Note 1500 -010 + 二级梯度线圈

VSM@SCM的问题 VSM样品11 2、样品形状： QD：磁性测量系列设备的标准参考样品 QD Application Note 1041 -001 PALLADIUM Reference Sample 2. 8 mm 3. 8 mm

VSM@SCM的问题 QD Application Note 1500 -015 VSM样品12

关于SQUID_VSM的ppt 以下蓝色背景的幻灯片均来自 William L. Zoeckler International Sales Manager Quantum Design

After Bill of QD, 2006 MPMS SQUID VSM System Newest member of the MPMS family of SQUID Magnetometers

After Bill of QD, 2006 MPMS SQUID VSM System Magnet power supply Commercial Computer (Not shown is the pump cabinet) System Electronics VSM linear motor drive Shielded nitrogen jacketed dewar

After Bill of QD, 2006 MPMS SQUID VSM Overview n n n The SQUID VSM is the latest member of the MPMS line of SQUID magnetometers. Offers SQUID sensitivity with the speed of a VSM Available in 7 tesla high homogeneity configuration Only a dc magnetometer that does not support other options Available now

After Bill of QD, 2006 MPMS SQUID VSM Benefits n n n Rapid. Temp is a innovative temperature control design that allows you to cool samples from room temperature to a stable 1. 8 K in ~30 minutes Quick. Switch offers you the ability to quickly and continuously ramp field, stabilize and acquire data up to 7 tesla New Fast. Lab data acquisition combines Quantum Design’s dc SQUID sensor and novel Vibrating Sample Magnetometer technology

After Bill of QD, 2006 MPMS SQUID VSM Temperature Control n n n Feature: Temperature Range: Cooling Rate: Temperature Stability: Temperature Accuracy: Sample Chamber I. D. : Rapid. Temp 1. 8 K to 400 K 30 K/min (300 K to 10 K stable in 15 min. ); 10 K/min (10 K to 1. 8 K stable in 5 min. ) +/- 0. 5% lesser of +/- 1% or 0. 5 K 9 mm

After Bill of QD, 2006 MPMS SQUID VSM Magnetic Field Control n n n Feature: Magnetic Field Range: Field Uniformity: Field Charging Rate: Field Charging Resolution: High-Tc Magnet Leads: Quick. Switch -70 k. Oe to +70 k. Oe 0. 01% over 4 cm 4 Oe/sec to 700 Oe/sec 0. 33 Oe Reduce Liquid Helium Boil-off 磁体电感： 30 H； 磁体电源： 3. 0 V B/I Ratio： 150 m. T/A

After Bill of QD, 2006 MPMS SQUID VSM Measurements n n n Fast. Lab 10 emu < 1 x 10 -8 emu @ zero field (4 sec. averaging); < 5 x 10 -8 emu @ 70 k. Oe (4 sec. averaging) Variable drive amplitude: 0. 1 to 5 mm (peak-to-peak) Variable drive frequency: 5 to 80 Hz (optimized at 28 Hz) Feature: Maximum DC moment: Sensitivity:

After Bill of QD, 2006 MPMS SQUID VSM n n n Power Requirements: Liquid Helium Usage: 190 VAC - 240 VAC; 50 -60 Hz; 1 -phase 4 liters/day (typical) + 0. 05 liters per sample cooldown Liquid Helium Capacity: 65 liters Liquid Nitrogen Usage: 5 liters/day (typical) Liquid Nitrogen Capacity: 60 liters Maximum Hold Time: 12 days (typical)

After Bill of QD, 2006 Sensitivity n n Ni. Fe thin film from NIST RMS noise < 10 -8 emu @ 4 sec average

After Bill of QD, 2006 Speed and Sensitivity n n 400 data points < 10 sec for each data point

After Bill of QD, 2006 Field Control n n zero field to 7 tesla in less than 2 minutes variable charging rate down to 4 Oersted per second

Temperature Control After Bill of QD, 2006 10 K – 2 K 2 minutes 300 K - 10 K 10 minutes n temperature range: 1. 8 - 400 K

SQUID_VSM（M 03组） Mössbauer 谱？

After Bill of QD, 2006 M(T) Validate Thermometers n A 99. 999% pure Indium wire sample (literature: Tc = 3. 40 K)

After Bill of QD, 2006 Sensitive M(T) Transitions Change in moment is 1 x 10 -7 emu n A small segment of Nb. Ti wire sample

After Bill of QD, 2006 Cold End of Probe Helium level meter Diode protection for magnet R&D probe has 2 SQUID capsules n Uses dc SQUID (instead of rf SQUID as in XL)

After Bill of QD, 2006 Sample Holders n fused silica paddle design centering washers (blue) n brass sample holder with Pd standard sample n

After Bill of QD, 2006 Sample Centering Response Function n Standard second order gradiometer design

After Bill of QD, 2006 Operational Comparison Instrument MPMS SQUID VSM MPMS XL PPMS VSM Sensitivity @ 7 T < 5 x 10 -8 emu < 6 x 10 -7 emu <3 x 10 -6 emu 4 -quad, 1 T, M(H) 500 data points 1. 5 hours 24 hours 0. 5 hours 300 K to 2 K stable < 0. 5 hours 2 hours 3 hours Liters L-He / day <4 l 7 l 4 l other options on platform • 800 K oven • SQUID-based cac • low field (0. 1 G) • cryocooled • sample rotation • optic probe • open platform • 1000 K oven • cac , torque • low field (0. 1 G) • cryocooled • sample rotation • heat capacity to 50 m. K • thermal transport • AC/DC resist. , Hall, I-V • Up to 16 T • open platform

After Bill of QD, 2006 MPMS SQUID VSM: Summary n VSM • dc SQUID sensor • < 10 -8 emu rms sensitivity at B=0 (4 second average) • < 5 x 10 -8 emu rms sensitivity at B = 7 T (4 sec average) • QD-designed VSM linear motor drive • Up to 5 VSM data points per second n Magnet • 4 - 700 Oe/sec charging rate • Charging to stable field in 1 second n Temperature • 1. 8 - 400 K • 300 K to stable 2 K in < 30 minutes

After Bill of QD, 2006 MPMS SQUID VSM Future Options n n n Ever. Cool Dewar configuration 1000 K Oven Availability within 12 months

关于PPMS_VSM的ppt 以下幻灯片均来自 William L. Zoeckler International Sales Manager Quantum Design

After Bill of QD, 2006 Vibrating Sample Magnetometer (VSM)

After Bill of QD, 2006 Vibrating Sample Magnetometer (VSM) n n n New VSM sample drive technology RMS Sensitivity of < 10 -6 emu or 0. 5% with 1 sec averaging (typical) Measurements to ~120 emu Complete measurement automation Easy to install and remove from the PPMS Optional 1000 K Oven

After Bill of QD, 2006 Vibrating Sample Magnetometer (VSM)

After Bill of QD, 2006 Design Features: Long-Throw Magnetic Linear Motor 48 -turn drive coil magnet banks ~6. 4 cm travel Iron flux return plates F=I B 10 -micron optical encoder

After Bill of QD, 2006 Design Features: Control Area Network (CAN) Electronics’ Module

After Bill of QD, 2006 VSM Sample Mounts

After Bill of QD, 2006 VSM Data

After Bill of QD, 2006 VSM Specifications n n n n n Sensitivity: Noise Floor: Accuracy: Oscillation Frequency: Oscillation Amplitude: Data Rate (typical): Accuracy: Largest Measurable Moment: Detection Coil Size: < 10 -6 emu/tesla 6 x 10 -7 emu rms < 5 x 10 -6 emu/tesla 40 Hz 0. 5 to 10 mm 1 Hz 0. 5% (using 2 mm spherical sample) ~ 120 emu 6. 3 mm I. D. 10. 2 mm I. D. (Optional; with 3 x 10 -6 emu/tesla sensitivity)

After Bill of QD, 2006 VSM Oven n n Stable temperature control from 300 to 1000 K Durable construction of the sample rod (carbon fiber) and sample holder (zirconia) Convenient, easy and strong sample mounting Minimized radiation heat leaks Sample rod Sample holder Top of sample rod with 5 -pin connector

After Bill of QD, 2006 VSM Oven Data

After Bill of QD, 2006 VSM Oven Specifications n Range of Temperature: 300 - 1000 K RMS Sensitivity: < 10 -5 emu or 0. 5% Noise Floor: < 10 -5 emu rms (H = 0) Accuracy: < 1 x 10 -5 emu/ tesla Temperature Precision: 0. 5 K Temperature Accuracy: 0. 5% n Requires High Vacuum Environment n n n

After Bill of QD, 2006 VSM Ultra-Low Field Capability n n Cancels magnet remanent field for very low field measurements Available on the 7 & 9 tesla longitudinal PPMS systems Automated software controlled process for nulling the remanent field Achieve fields of ± 0. 1 gauss (typical)