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Part of the 29 mm family of probes designed for the narrow space of our high-field, 830 MHz NMR magnet.
The probe is equipped with custom miniature stator developed by Ago Samosan (ICBP, Tallinn, Estonia).
It uses standard 4 mm zirconia rotors from Bruker with spinning speeds up to 10 kHz.
The RF channel can be tuned to most low-gamma nuclei by replacing frequency insert in the probehead.
This general-purpose probe is used for solid state NMR applications in a variety
of materials such as glasses, zeolites, or semiconductors — for observation of
low-gamma nuclei such as
99Ru,
109Ag,
49Ti,
25Mg,
67Zn,
33S, mid-gamma nuclei like
27Al,
23Na, and others.
High magnetic fields not only provide much needed sensitivity but higher
Larmor frequencies also reduce the probe ring-down time.
25Mg MAS (@ 10 kHz) spectrum of PMN at 19.6 T
(Gina Hoatson, College of Williams and Mary) |
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NORMAL
Use this table to select frequency insert for your nucleus.
Q values are loaded values for probe with no sample+.
Tuning range for each insert, F min...F max, is defined as frequency range
where RF reflection is less than -35dB.
Insert
(pF) |
F min
(MHz) |
F max
(MHz) |
Isotopes |
Q
(@ -3dB) |
| 85 |
37.7 |
39.5 |
105Pd,
99Ru,
109Ag,
39K,
163Dy |
71 |
| 54 |
45.2 |
48.3 |
143Nd,
49Ti,
47Ti,
53Cr |
72 |
| 45 |
48.3 |
52.3 |
25Mg,
67Zn |
75-77 |
| 37 |
52.2 |
57.3 |
95Mo,
201Hg,
97Mo,
43Ca |
77-81 |
| 28 |
57.8 |
65.2 |
14N,
33S,
189Os |
84-87 |
| None |
98.8 |
139 |
175Lu,
181Ta,
123Sb,
133Cs,
17O,
9Be,
139La,
6Li,
2H,
209Bi |
110-126 |
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HIGH POWER
These configurations are used when high RF field is absolute necessity, for example during the MQMAS experiments.
Such balanced circuitry can tolerate up to 2X higher RF field.
+ The so-called "unloaded" Q value (-7 dB) is 2 times the "loaded" Q.
++ If isotope is not in the table contact Peter Gor'kov to arrange new insert.
Table below shows values of bearing and drive pressures for MAS stator using manual controller.
The values are approximate and may vary with packing accuracy.
Bearing pressure
(Bars) |
Drive pressure
(Bars) |
Spinning speed
(Hz) |
| 3.0 |
0.5 |
3900 |
| 3.0 |
1.0 |
6200 |
| 3.0 |
1.5 |
7800 |
| 3.0 |
2.0 |
9300 |
| 3.0 |
2.5 |
10500 |
| 3.0 |
3.0 |
11600+ |
| 3.5 |
3.5 |
12600+ |
| 3.5 |
4.0 |
13400+ |
| 3.5 |
4.5 |
14000+ |
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+Note:
while this stator can reach higher speeds, it was designed for routine spinning at 10000 Hz and less.
Overspinning is risky and increases possibility of rotor crash.
...using this intrument
1. G. Wu et al., J. Am. Chem. Soc. 125 7182-7183 (2003), PDF
2. A. Wong et al., Phys. Chem. A 108 (47), 10551 (2004), PDF
3. J.B.D. Lacaillerie et al., J. Phys. Chem. B, 109, 14033 (2005), PDF
4. J.B.D. Lacaillerie et al., Cement Concrete Res, 36 (9), 1781 (2006), PDF
5. P. Duxson et al., Ind. Eng. Chem. Res. 45, 9208-9210 (2006), PDF
6. S. Prasad et al., J. Non-Crystalline Solids, 352 (26-27), 2834 (2006), PDF
7. A. Wong et al., J. Phys. Chem. A, 110 (33), 10084 (2006), PDF
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