Objective: Demonstrate electron spin resonance in DPPH
Electron spin resonance (ESR) is based on the energy absorption by substances with unpaired electrons, which are inside an external magnetic field produced by a DC source. The energy is absorbed from a high-frequency AC-generated field which is fed in perpendicular to the field from the DC source. If the frequency of the alternating field is equal to the resonant frequency, the impedance of the transmitting coil filled with the test material changes in accordance with a resonance curve and a peak will be visible on an oscilloscope screen. One suitable material for this is diphenyl-picry-hydrazyl (DPPH).
![Experiment: Electron spin resonance (230 V, 50/60 Hz), 8000720 [UE5030100-230], Magnetic Resonance](/imagelibrary/UE5030100-230/UE5030100-230_01_Experiment-Electron-spin-resonance-230-V-5060-Hz.jpg)
![Experiment: Electron spin resonance (230 V, 50/60 Hz), 8000720 [UE5030100-230], Magnetic Resonance](/thumblibrary/UE5030100-230/UE5030100-230_01_1200_1200_Experiment-Electron-spin-resonance-230-V-5060-Hz.jpg)
![HF Patch Cord, 1m, 1002746 [U11255], Experiment Leads and Cables](/thumblibrary/U11255/U11255_01_140_140_HF-Patch-Cord-1m.jpg)
![Digital Multimeter P3340, 1002785 [U118091], Hand-held Digital Measuring Instruments](/thumblibrary/U118091/U118091_01_140_140_Digital-Multimeter-P3340.jpg)
![PC Oscilloscope 2x25 MHz, 1020857 [U11830], Oscilloscopes](/thumblibrary/U11830/U11830_01_140_140_PC-Oscilloscope-2x25-MHz.jpg)
![Digital Oscilloscope, 2x30 MHz, 1020910 [U11834], Oscilloscopes](/thumblibrary/U11834/U11834_01_140_140_Digital-Oscilloscope-2x30-MHz.jpg)
![Set of 15 Safety Experiment Leads, 75 cm, 2.5 mm², 1002843 [U138021], Circuits](/thumblibrary/U138021/U138021_01_140_140_Set-of-15-Safety-Experiment-Leads-75-cm-25-mm.jpg)
![DC Power Supply 20 V, 5 A
(230 V, 50/60 Hz), 1003312 [U33020-230], Power Supplies](/thumblibrary/U33020-230/U33020-230_01_140_140_DC-Power-Supply-20-V-5-A-230-V-5060-Hz.jpg)
![HF Patch Cord, BNC/4 mm Plug, 1002748 [U11257], Experiment Leads and Cables](/thumblibrary/U11257/U11257_01_140_140_HF-Patch-Cord-BNC4-mm-Plug.jpg)
![Universal Clamp, 1002830 [U13255], Clamps](/thumblibrary/U13255/U13255_01_140_140_Universal-Clamp.jpg)
![Control Unit for Spectrum Lamps (230 V, 50/60 Hz), 1021409 [U219051-230], Spectrum Tubes and Spectrum Lamps](/thumblibrary/U219051-230/U219051-230_01_140_140_Control-Unit-for-Spectrum-Lamps-230-V-5060-Hz.jpg)
![Spectrometer-Goniometer S, 1008673 [U22050], Spectrophotometer](/thumblibrary/U22050/U22050_01_140_140_Spectrometer-Goniometer-S.jpg)
![Transformer with Rectifier 3/6/9/12 V, 3 A (230 V, 50/60 Hz), 1003316 [U33300-230], Power Supplies](/thumblibrary/U33300-230/U33300-230_01_140_140_Transformer-with-Rectifier-36912-V-3-A-230-V-5060-Hz.jpg)
![Plexiglas Plate, 1000880 [U8476371], Electrostatics](/thumblibrary/U8476371/U8476371_01_140_140_Plexiglas-Plate.jpg)
![Spectral Lamp Na, 1003541 [U8476840], Spectrum Tubes and Spectrum Lamps](/thumblibrary/U8476840/U8476840_01_140_140_Spectral-Lamp-Na.jpg)
![N-Doped Germanium on Printed Circuit Board, 1009760 [U8487030], Hall-effect](/thumblibrary/U8487030/U8487030_01_140_140_N-Doped-Germanium-on-Printed-Circuit-Board.jpg)
![Analogue Multimeter ESCOLA 100, 1013527 [U8557380], Hand-held Analog Measuring Instruments](/thumblibrary/U8557380/U8557380_01_140_140_Analogue-Multimeter-ESCOLA-100.jpg)
![Experiment: Dielectrics in plate capacitors (230 V, 50/60 Hz), 8000786 [UE3010850-230], Electrostatics](/thumblibrary/UE3010850-230/UE3010850-230_01_140_140_Experiment-Dielectrics-in-plate-capacitors-230-V-5060-Hz.jpg)
![Experiment: Millikan’s Experiment (230 V, 50/60 Hz), 8000774 [UE5010400-230], Fundamentals of Atomic Physics](/thumblibrary/UE5010400-230/UE5010400-230_01_140_140_Experiment-Millikan-s-Experiment-230-V-5060-Hz.jpg)
![Experiment: Hall-effect in semiconductors (230 V, 50/60 Hz), Basic equipment, 8000728 [UE6020200-230], Conduction Phenomena](/thumblibrary/UE6020200-230/UE6020200-230_01_140_140_Experiment-Hall-effect-in-semiconductors-230-V-5060-Hz-Basic-equipment.jpg)