We offer Dependence of Hall Coefficient on Temperature usefull in physics and material science lab. The Hall voltage for p-carriers has opposite sign from that for n-carriers. Therefore if a semiconductor with p-type doping is gradually heated up, more and more electrons from its valence band will go to conduction band. As a result hall voltage would fall rapidly with temperature and even become zero or change sign. At the point of zero Hall Coefficient, it is possible to determine the ratio of mobilities b=µe/µh. The Hall coefficient inversion is a characteristic of only p-type semiconductors. The set-up consists of the following: 1. Hall Probe (Ge: p-type), HPP-22 Ge single crystal with four spring type pressure contacts is mounted on a glass-epoxy strip. Leads are provided for connections with the current source and Hall voltage measuring devices. Oven It is a small oven which could be easily mounted over the crystal or removed if required. Temperature Sensor Cromel-Alumel thermocouple with its junction at a distance of 1mm from the crystal. 2. Hall Effect Set-up :DHE-22 The set-up, DHE-22 consists of two sub set-ups, each consisting of further two units. Measurement of Probe Current & Hall Voltage This unit consists of digital millivoltmeter and constant current power supply. The Hall voltage and probe current can be read on the same digital panel meter through a selector switch. (a) Digital Millivoltmeter Specifications Range: 0-200mV (100µV min.) Accuracy: ±0.1% of reading ±1 digit Impedance: 1MΩ (b) Constant Current Power Supply Specifications Current: 0-20mA (10µA min) Accuracy: ±0.2% of the reading or ±1 digit Load regulated: 0.05% for 0 to full load Line regulation: 0.05% for 10% variation Measurement of Thermo emf and Heater current The unit consists of a digital millivoltmeter and constant current power supply. The thermo emf of thermocouple and heater current can be read on the same DPM through a selector switch. (a) Digital Millivoltmeter Specifications : Range: 0-20mV Resolution: 10µV equivalent to 0.25°C in terms of thermo emf Accuracy: ±0.1% of reading ±1 digit (b) Constant Current Power Supply Specifications Current: 0-1A Accuracy: ±0.2% of the reading ±1 digit Line regulation: 0.1% for 10% variation Load regulated: 0.1% for 0 to full load 5. Electromagnet, EMU-50V 6. Constant Current Power Supply, DPS-50 7. Digital Gaussmeter, DGM-202/ DGM-102 The experiment is complete in all respect.

We offer Dependence of Hall Coefficient on Temperature usefull in physics and material science lab. The Hall voltage for p-carriers has opposite sign from that for n-carriers. Therefore if a semiconductor with p-type doping is gradually heated up, more and more electrons from its valence band will go to conduction band. As a result hall voltage would fall rapidly with temperature and even become zero or change sign. At the point of zero Hall Coefficient, it is possible to determine the ratio of mobilities b=µe/µh. The Hall coefficient inversion is a characteristic of only p-type semiconductors. The set-up consists of the following: 1. Hall Probe (Ge: p-type), HPP-22 Ge single crystal with four spring type pressure contacts is mounted on a glass-epoxy strip. Leads are provided for connections with the current source and Hall voltage measuring devices. Oven It is a small oven which could be easily mounted over the crystal or removed if required. Temperature Sensor Cromel-Alumel thermocouple with its junction at a distance of 1mm from the crystal. 2. Hall Effect Set-up :DHE-22 The set-up, DHE-22 consists of two sub set-ups, each consisting of further two units. Measurement of Probe Current & Hall Voltage This unit consists of digital millivoltmeter and constant current power supply. The Hall voltage and probe current can be read on the same digital panel meter through a selector switch. (a) Digital Millivoltmeter Specifications Range: 0-200mV (100µV min.) Accuracy: ±0.1% of reading ±1 digit Impedance: 1MΩ (b) Constant Current Power Supply Specifications Current: 0-20mA (10µA min) Accuracy: ±0.2% of the reading or ±1 digit Load regulated: 0.05% for 0 to full load Line regulation: 0.05% for 10% variation Measurement of Thermo emf and Heater current The unit consists of a digital millivoltmeter and constant current power supply. The thermo emf of thermocouple and heater current can be read on the same DPM through a selector switch. (a) Digital Millivoltmeter Specifications : Range: 0-20mV Resolution: 10µV equivalent to 0.25°C in terms of thermo emf Accuracy: ±0.1% of reading ±1 digit (b) Constant Current Power Supply Specifications Current: 0-1A Accuracy: ±0.2% of the reading ±1 digit Line regulation: 0.1% for 10% variation Load regulated: 0.1% for 0 to full load 5. Electromagnet, EMU-50V 6. Constant Current Power Supply, DPS-50 7. Digital Gaussmeter, DGM-202/ DGM-102 The experiment is complete in all respect.