Fig. 1

Principle of electron paramagnetic resonance[1]

Fig. 2

Simulated powder pattern EPR spectra for the tryptophan radical in tyrosine-depleted azurin mutant (AzC-W48) at different microwave frequencies producing electron spin resonance. (a) W-band (95 GHz); (b) 350 GHz; (c) 700 GHz[6]

Fig. 3

The relationship between electron spin polarization and temperature for S = 1/2 system with g = 2 at two different microware frequencies[5]

Fig. 4

Average EPR spectra of the motion of spin-labeled molecules at different microwave frequencies in a nitrogen oxide with rotational correlation time of 1.7 ns[19]

Fig. 5

The key timeline in the development of EPR spectrometer abroad

Table 1

Distribution of high magnetic field EPR devices in Europe and America

Table 2

Distribution of high magnetic field EPR devices in Japan[4]

Fig. 6

General structure diagram of high frequency and high field continuous wave EPR spectrometer

Fig. 7

Schematic diagram of a multifrequency high field EPR spectrometer operating in the single-pass transmission mode[33]

Fig. 8

Structure diagram of 230/115 GHz high frequency and high field continuous wave/pulse EPR spectrometer[37]

Fig. 9

The first set of pulsed high magnetic field and high frequency EPR device built by National Pulsed High Magnetic Field Science Center in China

Fig. 10

The steady state high magnetic field EPR test equipment set up by High Magnetic Field Laboratory, Chinese Academy of Sciences

Fig. 11

Overall design of 15 T superconducting magnet

Fig. 12

Circuit diagram of 400~420 GHz high frequency microwave solid-state source

Fig. 13

Overall design drawing of high frequency and high field EPR measuring rod

Fig. 14

Design of metal shield cabinet and simulation analysis of the shielding effect

Fig. 15

User operation interface of the EPR experimental measurement system

Fig. 16

(a) 94 GHz pulse EPR spectra of the synthesized HA doped with Mn2+ and the stable and unstable AP at T=50 K; (b) 94 GHz pulse EPR spectra of TCP doped with Mn2+ at T=50 K and 100 K[39]

Fig. 17

The combination of low-field X band EPR spectra and high-field 240 GHz EPR spectra of AsymPol-POK and cAsymPol-POK. AsymPol-POK is represented by black solid line, cAsymPol-POK is represented by blue solid line, and corresponding simulated EPR spectra are represented by red dotted line[40]

Fig. 18

230 GHz continuous wave EPR spectra of 50 nm ND samples before and after air annealing. The upper right illustration shows P1 and surface spin (S) contribution to the EPR spectrum; On the left is a drawing representing NDS during annealing. The green solid line represents the EPR experimental spectrum, the red arrow represents the center of P1, and the blue arrow represents the surface spin[48]

Fig. 19

EPR spectra of sample (n-Bu3NH)2[V(C6H4O2)3] detected by 120 and 240 GHz microwave signals at 4 K and 4.5 K, respectively. The green and purple solid lines are EPR experimental spectra, and the black solid lines are EPR simulation spectra[49]

Fig. 20

(a) 94 GHz continuous wave EPR spectra in YAG:Ce,Yb ceramics at 1.5 K. The dashed lines are the EPR simulation spectra of Yb3+ and Ce3+ in powder materials. The illustrations are the EPR spectra of Gd3+ in YAG:Ce,Gd single crystals in different directions; (b) 94 GHz continuous wave EPR spectra in YAG:Ce,Cr ceramics at 1.5 K and 5 K, and dashed lines are EPR simulation spectra of Ce3+, Cr3+ and Gd3+ in powder materials[50]