Facilities & Equipment

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From Physlab.lums.edu.pk

Spectroscopic Ellipsometer

Woollam's alpha-SE ellipsometer is used for rapid measurement of refractive indices and film thickness. Wavelengths range between 180 and 900 nm and multiple incidence angles are possible.

Stereo microscope

A trinocular stereo zoom microscope, SMZ-168TL manufactured by Motic, allows convenient and fast microscopy with illuminated or transmitted light. Sets of polarizers allow polarized light microscopy and a digital camera enables image recording. We also have a cold light source for illumination.

Spin coater

VTC-100 compact spin coater manufactured by MTI corporation is designed for material research lab to make quality sol-gel coating at easy and quick upto 4" wafer. The spin speed is variable from 500-8000 rpm with two programmable segments.

Sputter coater

We have started working in our group on thin film fabrication and study their magneto-optical properties. We are fabricating thin films by deposition technique using Denton Desk V HP Sputter Coater under vacuum. This unit is designed to deposit a conductive coating on a substrate (glass). The coating thickness can be controlled by head mounted crystal sensor and thickness monitor.

Calibration data for gold sputtering at current of 40 mA (data from 1 February 2013)

Furnaces

We have two laboratory furnaces including Vacuum Tube Furnace (XD-1200NT) and XD-1200N Muffle Furnace having the working temperature of 1100 degree Celsius. These furnaces are being in use to sinter or anneal synthesized materials.

Grinder/polisher

This compact 8" Grinder, Lapper, Polisher is well suited for manual finishing of embedded specimens using PSA backed grinding, lapping and polishing (cloths) discs. The housing is made from non-corroding sturdy plastic. The durable 1/4 HP motor has a variable speed control for 80-2000 rpm to select the optimum speed for grinding or polishing. The XP 8 includes a flexible and variable water spout for grinding applications.

pH meter

AD-8000 is a microprocessor-based pH, ORP, conductivity, TDS and temperature bench meter. pH measurements are compensated for temperature effect automatically (ATC) using AD5006 temperature probe, while the EC readings can be compensated automatically (ATC) using the conductivity probe with built in temperature sensor or manually (MTC). It is also possible to disable the temperature compensation and measure the actual conductivity.

Analytical balance

The FA/JA series electronic balance is used to measure masses in a capacity of 0.0001 g. This analytical instrument is used to take precise measurement of masses. This system can also be interfaced with computer to take digital data in printed form.

Ball mill

A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals and ceramic raw materials. Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls. In our lab, we have a mini ball mill which is used to grind course powder in to fine particles,

Diamond cutter

Mini cut off saw is used to cut hard materials like ceramics who has the hardness less than diamond. It has a diamond cutter to cut the materials in two pieces.

Nanovoltmeter

The two-channel Model 2182A Nanovoltmeter is optimized for making stable, low noise voltage measurements and for characterizing low resistance materials and devices reliably and repeatably.

Precision current source

The Model 6221 AC and DC Current Source combine ease of use with exceptionally low current noise. Low current sourcing is critical to applications in test environments ranging from R&D to production, especially in the semiconductor, nanotechnology, and superconductor industries. High sourcing accuracy and built-in control functions make the 6221 ideal for applications like Hall measurements, resistance measurements using delta mode, pulsed measurements, and differential conductance measurements.

Picoammeter

The 5-1/2 digit Model 6485 Picoammeter combines Keithley's expertise in sensitive current measurement instrumentation with enhanced speed and a robust design. With eight current measurement ranges and high speed autoranging, this cost-effective instrument can measure currents from 20fA to 20mA, taking measurements at speeds up to 1000 readings per second.

Low temperature cryostat

The Physlab is equipped with a low-temperature, closed cycled helium cryostat, compressor, vacuum unit and water chiller / re-circulator. The cryostat is fitted with quartz optical windows, a Cernox temperature sensor and a 25 W heater. The cryostat can achieve temperatures in the vicinity of 7 K when subject to a vacuum of 1 mtorr.

Variable temperature electrical conductivity measurement

With the help of the four probe technique, it is possible to eliminate voltage drops in measurement leads allowing accurate determination of low and medium range resistivities. At the physlab, we have developed sample holders with four needles in the collinear and van der Pauw configurations, for the measurement of electrical resistivities. Equipped with a high temperature oven, close cycle helium cryostat and temperature controllers, we can routinely make measurements from 10 to 780 K. A precision current source and nanovoltmeter are used for the measurements. These computer controlled instruments can be operated in the delta configuration allowing the compensation of thermally induced voltages.

How to do conductivity measurement
Labview file for delta measurement using Keithley's 2182A and 6221AC/DC
Connection schematic for resistivity measurements
User manual for four-probe and Van der Pauw setups

X-Ray Flourescence (XRF) system

The Physlab has assembled a low cost energy dispersive X-ray fluorescence (XRF) system to carry out the elemental analysis of different materials. The assembly to place the samples is constructed in the physlab workshop and analysis of different materials is carried out using this XRF system. The XRF system will ease the analysis of materials commonly used in the lab and also help in studying the archeological sites in our city. The XRF system will be used in the Physlab for:

1) Examination and historical coregistration of (a) coinage, (b) manuscripts and (c) metal wear preserved in Lahore's museums and archeological sites. 2) Quantitative compositional analysis of thin films grown in the lab.

CNC Machining Centre

The Physlab has recently acquired a CNC machine (CNC Lathe Smart 32-T8, manufactured in Taiwan). This will boost the manufacturing capabilities of the Laboratory, making possible the fabrication of high precision components and equipment for scientific research. This is the latest addition to the Physics Lab Workshop. The machine is equipped with Fanuc control.

High temperature precision dielectric measurement system

Dielectric Measurements are a basic means of evaluating electronic components and materials. Every material has a unique set of electrical characteristics that are dependent on its dielectric or insulation properties. Accurate measurements of these properties can provide valuable information to ensure an intended application. The dielectric cell is successfully designed and constructed for measuring frequency and temperature dependent dielectric properties of rigid flat materials such as Ceramics, Polymers and composites at elevated temperatures. The cell is classified in vertical and horizontal assembly that can be used up to 300 Degrees C and up to 800 Degrees C respectively. The cell is made up of two electrodes. One electrode is fixed and the other is movable with a guard ring via a micrometer. The micrometer allows precise measurement of electrode spacing. The guard ring reduces fringe effects to improve measurements. The cell can be connected to LCR meter through probes and is interfaced with computer through software wizard that will allow to control the LCR via DB-9 cable and perform linear or log sweeps over a frequency range 20Hz to 1MHz as well as save the measurement results to a log file.

Operator Manual
Designing a dielectric cell
Precise High Temperature Dielectric Measurement System

PCB Manufacturing Facility

User Manual
CCD2
ISOCAM

With the passage of time the need of being independent from the outside market has significantly increased and physics lab is approaching this goal by developing specific expertise and manufacturing skills in the lab. Moreover, making complex circuit on Vero board was time consuming and prone to error. Previously PCB manufacturing was done from Hall road or through chemical etching in the lab. Recently, the Physlab has acquired CNC based CCD PCB machine. The machine is capable of routing and drilling copper boards. The machine works on the principle of isolation milling. The workstation comprises of a dedicated personal computer with driver software and Isocam, vacuum cleaner (for sucking dust while spindle is running) and a power supply unit. We have Tungsten carbide routers of diameter 0.6 mm and drill bits of 1.2mm, 0.5mm, 0.3mm and 3mm size. Physics lab opens this facility to SSE Faculty. One just needs to email Gerber files at Muhammad Wasif. If anyone seeks to learn this machine thoroughly, contact Muhammad Wasif for appointment. For bulk student tasks, contact Dr. Sabieh Anwar. Commercial usage of the facility can also be discussed.