Many investigation lines in this institute rely on the magnetic and electric properties of the materials being investigated. Most of the characterization carried out requires the use of very precise measurement systems. In order to satisfy the intensive demand of measurements of this nature, the Low Temperature and Magnetometry Service was created.
The Low Temperature and Magnetometry Service is part of the ICMAB Scientific Technical Services Unit and its facilities are available to all the research crew of the Institute, as well as, to external users. It is devoted to the measurement of the magnetic, electric properties under specific conditions of external magnetic field and temperature.
In order to achieve the demand, the Service is equipped with two SQUID based magnetometers (Quantum Design MPMS system), devoted to magnetometry measurements and two Quantum Design PPMS systems, devoted to electrical transport measurements, as well as magnetometry measurements.
A User Commission supervises the proper operation of the Service and meets once a year in order to satisfy this supervision task as well as to take the appropriate decisions for the optimization of the Service operation.
Technicians
Scientists in charge
User's Committee
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- Maximum field: ±70kOe
- Temperature range: 2K-400K
- Two measurement modes: DC (continuous sample motion through the picking coils) and RSO (oscillatory motion through the pickup coils)
- Sensivity at zero applied field, magnet in persistent mode: 10-5emu for DC mode, 10-7emu for RSO mode
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- UItra-Low field option: Useful for ensuring real zero field cooling processes, since the option is able to cancel the mangetic field at a certain working point. Edit
Quantum Design MPMS-3
The MPMS-3 system is the new generation of SQUID detector based magnetometers. It offers an enchanced performance of temperature stabilization, magnetic field stability when compared to those exhibited by the MPMS-XL system. This fact reduces the measurement noise, allowing the obtention of cleaner measurements for those samples with extremelly low magnetic moment. The core system consists of a superconducting longitudinal solenoid able to generate mangetic fields up to 70kOe. The system has also able to precisely control the temperature at the sample space at any value from 2K to 400K with a stability condition of less than 0.1% of oscillation.
SPECIFICATIONS
- Maximum field: ±70kOe
- Temperature range: 2K-400K
- Two measurement modes: DC (continuous sample motion through the pick-up coils) and VSM (vibration sample motion around the center of the pick-up coils)
- Sensivity at low field: 10-7emu for DC mode, 10-8emu for VSM mode
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Core system
PPMS System bundles the same core system as the MPMS-XL, except for the SQUID detection system. A pinout system is available instead, thus making it possible to electrically contact the sample under study and measure its transport properties (resistance, Hall effect, magnetoresistance…). The core system makes possible to generate magnetic fields up to 90kOe and to control the sample space temperature to any value between 2K and 400K with a stability condition of less than 0.1% of oscillation. PPMS is not only limited to electrical measurements, since the electrical contacts at the sample chamber can be used as an interface to more sofisticated measurement systems such as a VSM magnetometer, AC Susceptometer… -
Specifications
- Maximum field: ±90kOe
- Temperature range: 2K – 400K (some setups modify this range, see below for more information)
MEASUREMENTS OPTIONS
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Resistivity
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AC Transport
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ACMS
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VSM
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Torque
Sample preparation
Due to the nature of the equipment used, restrictions apply on the type of samples that can be submitted. The service will only accept samples that are prepared following the tips explained below.
- MPMS-XL & MPMS3
- PPMS - Resistivity & AC Transport
- PPMS -VSM Low Temperature
- PPMS-VSM Oven
- PPMS-AC Susceptibility
- PPMS-Torque
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MPMS-XL & MPMS3
Powder
- Material in powder form must be delivered inside gelatine or pollycarbonate capsules and the user is responsible of putting the powder inside the capsules. User must ensure that no powder can escape from the capsule, so that equipment contamination is avoided.
- Do not manipulate the material with potentially magnetic tweezers, spatules, etc. since it could introduce false contributions to the magnetic signal.
- Gelatin capsules degrade with humidity. Avoid its contact to any polar solvents or direct contact to skin.
- For ferromagnetic or ferrimagnetic materials, it is advised to look for the expected saturation magnetization and limit the mass if the expected magnetic moment would be larger than 0.5emu.
- NO LIQUID SAMPLES ARE ALLOWED. IF ANY SOLVENT IS USED, IT MUST BE FIRST EVAPORATED!
- Capsules are provided by the service.
Thin films
- Sample width cannot be greater than 6mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- The ideal form factor is a square of 5x5mm2
- Make sure that the back side of the substrate does not contain any trace of silver paste, sticky tape or any other material that could eventually trap metallic particles.
Bulk samples
- Sample width cannot be greater than 6mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- Due to the large amount of mass, user should ensure that the expected magnetic moment is not larger than 0.5emu. If so, it should be considered the possibility of further reducing the sample size.
- If the material under study is brittle a gelatin capsule or any other kind of protection must be used in order to avoid to contaminate the sample chamber.
Other samples
- Contact to the Service Technician in order to study the case.
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PPMS - Resistivity & AC Transport
- Only bulk samples or thin films can be measured by this technique.
- Sample must be contacted to the puk sample holder using a four-wire schema. Wire-bonding contacts and silver paste assisted contacts can be used depending on the nature of the sample.
- Wires and silver paste are not provided by the service.
- Wire-bonding facility is available in the Nanoquim platform.
- Service can lend sample holders for both AC Transport and Resistivity options (rotator version and regular version) for a limited period of time.
- Contact to the Service Manager for more details.
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PPMS -VSM Low Temperature
Powder
- Material in powder form must be delivered inside gelatine or pollycarbonate capsules and the user is responsible of putting the powder inside the capsules. User must ensure that no powder can escape from the capsule, so that equipment contamination is avoided.
- Do not manipulate the material with potentially magnetic tweezers, spatules, etc. since it could introduce false contributions to the magnetic signal.
- Gelatin capsules degrade with humidity. Avoid its contact to any polar solvents or direct contact to skin.
- NO LIQUID SAMPLES ARE ALLOWED. IF ANY SOLVENT IS USED, IT MUST BE FIRST EVAPORATED!
- Capsules are provided by the service.
Thin films
- Sample width cannot be greater than 10mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- The ideal form factor is a square of 5x5mm2
- Make sure that the back side of the substrate does not contain any trace of silver paste, sticky tape or any other material that could eventually trap metallic particles.
Bulk samples
- Sample width cannot be greater than 10mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- If the material under study is brittle a gelatin capsule or any other kind of protection must be used in order to avoid to contaminate the sample chamber.
Other samples
- Contact to the Service Technician in order to study the case.
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PPMS-VSM Oven
- The experimental setup limits sample width to 3mm. Sample will be mounted using Al2O3 cement diluted with water. Please, ensure that this glue system does not harm your material.
- Powder samples should be pressed into pellets or embedded with other matrix material that does not degrade at high temperature. Al2O3 cement can be used in this case.
- Bulk samples and thin films can be used with no problem as long as their width is less than 3mm.
Please, contact to the Service Manager for more details
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PPMS-AC Susceptibility
Powder
- Material in powder form must be delivered inside gelatine or pollycarbonate capsules and the user is responsible of putting the powder inside the capsules. User must ensure that no powder can escape from the capsule, so that equipment contamination is avoided.
- Do not manipulate the material with potentially magnetic tweezers, spatules, etc. since it could introduce false contributions to the magnetic signal.
- Gelatin capsules degrade with humidity. Avoid its contact to any polar solvents or direct contact to skin.
- NO LIQUID SAMPLES ARE ALLOWED. IF ANY SOLVENT IS USED, IT MUST BE FIRST EVAPORATED!
- Capsules are provided by the service.
Thin films
- Sample width cannot be greater than 6mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- The ideal form factor is a square of 5x5mm2
- Make sure that the back side of the substrate does not contain any trace of silver paste, sticky tape or any other material that could eventually trap metallic particles.
Bulk samples
- Sample width cannot be greater than 6mm. Despite there is no theoretical limitation on the height, it is advised to be as short as possible in order not to degrade the reliability of the reported value.
- If the material under study is brittle a gelatin capsule or any other kind of protection must be used in order to avoid to contaminate the sample chamber.
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PPMS-Torque
The experimental setup allows only the use of bulk samples or thin fims not larger than 1x1mm2. The desired rotation must be clearly indicated either in the sample, or by using a drawing sketch.
Only bulk or thin film samples are accepted
Low Temperatures and
Magnetometry Service
Address:
ICMAB
Campus UAB
(in front of Firehouse)
08193, Bellaterra
Spain