scholarly journals In Situ Compensation Method for Precise Integral SQUID Magnetometry of Miniscule Biological, Chemical, and Powder Specimens Requiring the Use of Capsules

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 495
Author(s):  
Katarzyna Gas ◽  
Maciej Sawicki

Steadily growing interest in magnetic characterization of organic compounds for therapeutic purposes or of other irregularly shaped specimens calls for refinements of experimental methodology to satisfy experimental challenges. Encapsulation in capsules remains the method of choice, but its applicability in precise magnetometry is limited. This is particularly true for minute specimens in the single milligram range as they are outweighed by the capsules and are subject to large alignment errors. We present here a completely new experimental methodology that permits 30-fold in situ reduction of the signal of capsules by substantially restoring the symmetry of the sample holder that is otherwise broken by the presence of the capsule. In practical terms it means that the standard 30 mg capsule is seen by the magnetometer as approximately a 1 mg object, effectively opening the window for precise magnetometry of single milligram specimens. The method is shown to work down to 1.8 K and in the whole range of the magnetic fields. The method is demonstrated and validated using the reciprocal space option of MPMS-SQUID magnetometers; however, it can be easily incorporated in any magnetometer that can accommodate straw sample holders (i.e., the VSM-SQUID). Importantly, the improved sensitivity is accomplished relying only on the standard accessories and data reduction method provided by the SQUID manufacturer, eliminating the need for elaborate raw data manipulations.

2022 ◽  
Author(s):  
Katarzyna Gas ◽  
Maciej Sawicki

Steadily growing interest in magnetic characterization of organic compounds for therapeutic purposes or of other irregularly shaped specimens calls for refinements of experimental methodology to satisfy experimental challenges. Encapsulation in capsules remains the method of choice, but its applicability in precise magnetometry is limited. This is particularly true for minute specimens in the single milligram range as they are outweighed by the capsules and are subject to large alignment errors. We present here a completely new experimental methodology that permits 30-fold in situ reduction of the signal of capsules by substantially restoring the symmetry of the sample holder that is otherwise broken by the presence of the capsule. In practical terms it means that the standard 30 mg capsule is seen by the magnetometer as approximately a 1 mg object, effectively opening the window for precise magnetometry of single milligram specimens. The method is shown to work down to 1.8 K and in the whole range of the magnetic fields. The method is demonstrated and validated using the reciprocal space option of MPMS-SQUID magnetometers; however, it can be easily incorporated in any magnetometer that can accommodate straw sample holders (i.e., the VSM-SQUID). Importantly, the improved sensitivity is accomplished relying only on the standard accessories and data reduction method provided by the SQUID manufacturer, eliminating the need for elaborate raw data manipulations.


2021 ◽  
Author(s):  
Katarzyna Gas ◽  
Maciej Sawicki

Steadily growing interest in magnetic characterization of organic compounds aiming at therapeutic purposes, or of other irregular-shaped specimens calls for refinements of experimental methodology to satisfy experimental challenges. Encapsulation in capsules remains the method of choice, but its applicability in precise magnetometry is limited. This is particularly true for minute specimens in single mg range since they are outweighed by the capsules and due to large alignment errors. We present here a complete new experimental methodology which permits 30-fold in situ reduction of the signal of capsules. In practical terms it means that the standard 30 mg capsule is seen by the magnetometer as about 1 mg object, effectively opening the window for precise magnetometry of single mg specimens. The method is shown to work down to 1.8 K and in the whole range of the magnetic fields. The method is demonstrated and validated using the reciprocal space option of MPMS-SQUID magnetometers, however it can be easily incorporated in any magnetometer which can accommodate straw sample holders (i.e. the VSM-SQUID). Importantly, the improved sensitivity is accomplished relying only on the standard accessories and data reduction method provided by the SQUID manufacturer, eliminating needs for an elaborate raw data manipulations.


2014 ◽  
Vol 809-810 ◽  
pp. 59-66
Author(s):  
Yun Long Li ◽  
Bin Huang Liu ◽  
Song Bai Lin

A novel kind of AgNPs catalyst was synthesized by in-situ reduction method using poly(2-acrylamido-2-methyl propyl sulfonic acid-co-2-hydroxyethyl methclate) [short as P(AMPS-co-HEMA)] hydrogel as matrices and AgNO3as a metal precursor. The structure of the composite hydrogel was characterized by Scan Electrical Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that AgNPs were binded with end group and most of the particles were isolated and uniformly distributed on the P(AMPS-co-HEMA). The catalytic properties in the reduction reaction of 4-nitrophenol(shorted as 4-NP) to 4-aminophenol(shorted as 4-AP) were studied in detail, and the result showed that conversion rate and conversion efficiency attained 97.56% and 0.9671 mmol/g·min when the amount of AgNPs was 9mg, [NaBH4] was 2.0×10−1mol/L, [4-NP] was 2.0×10−2mol/L and the total volume of solution was 50 mL, respectively.


CrystEngComm ◽  
2014 ◽  
Vol 16 (7) ◽  
pp. 1322-1333 ◽  
Author(s):  
Shuijin Lei ◽  
Lei Liu ◽  
Chunying Wang ◽  
Xiaolian Shen ◽  
Donghai Guo ◽  
...  

Author(s):  
Kota Yamamoto ◽  
Hisashi Asanuma ◽  
Hiroaki Takahashi ◽  
Takafumi Hirata

New data reduction method for isotopic measurements using high-gain Faraday amplifiers enables precise uranium isotopic analysis even from transient signals.


2014 ◽  
Vol 3 (2) ◽  
pp. 179-185 ◽  
Author(s):  
P. P. Ebner ◽  
S. A. Grimm ◽  
M. Schneebeli ◽  
A. Steinfeld

Abstract. An instrumented sample holder was developed for time-lapse microtomography of snow samples to enable in situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4-day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.


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