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A thorough analysis of the spin–spin relaxation and 55 Mn NMR line shape revealed that in the number of manganites, including La 0.7 Ca 0.3 MnO 3 and La 0.7 Sr 0.3 MnO 3 , two different ferromagnetic phases with mobile holes coexisted below T C in a certain temperature interval, which depended on the composition. The phase with lower hyperfine field has a faster nuclear relaxation, and its volume decreases with decreasing temperature.

NMR spectra of 57 Fe nuclei in Tm x Y 3− x Fe 5 O 12 garnets were studied for low ( x =0.2) and high ( x =2.8) concentrations of Tm in the temperature region 1.8–180 K. Analysis of the temperature evolution of the spectra indicates that for T → 0 K the magnetic moments of two inequivalent Tm 3+ ions deviate from the direction of overall magnetization by more than 6° and 12°, respectively. The projection of one of the moments on the direction of magnetization was found to be ( T → 0 K) 1.6 (4) μ B . On the basis of the results obtained a novel approach to the determination of the noncollinear magnetic structure in rare-earth iron garnets is proposed.

We report the NQR on Ba nuclei in four samples of BaBiO 3 prepared in different ways. The spectra of 137 Ba consist of broad line centered near 18 MHz at 4.2 K. The broadening of NQR suggests a local distortions of the crystal structure. The area under the line for ceramic sample BaBiO 3 synthesized at 800°C is approximately two times larger comparing to ceramic samples and single crystal prepared at 930–1080°C. The decrease of the NQR signal is attributed to the partial disordering of charge disproportionating Bi ions on the two inequivalent sites.

NMR on 55 Mn nuclei was measured in Pr 1 − x Ba x MnO 3 ( x = 0.2, 0.25). Complex NMR spectra between 290 and 430 MHz were observed at 61 K. For x = 0.25 the transformation of NMR spectrum due to the transition between localized and delocalized holes is observed when the temperature is increased, similar to that reported previously for x = 0.3. For x = 0.2 the signal is too weak, to measure the temperature dependence.

The effects of hydrostatic pressure up to 1.3 GPa on the Neel temperature in orthorhombic antiferromagnetic La 2 CuO 4+δ have been investigated using the 139 La NQR method. A positive sign of the pressure derivative, d T N /d P = 7.1 K/GPa, as well as an increase in the critical index β from 0.29 at ambient pressure to 0.33 at 1.3 GPa have been observed. The results were processed using the Green function method.

The 57Fe NMR spectra in yttrium iron garnets (YIG) containing low concentrations of the nontrivalent cations Ca2+ and Si4+ were measured. The analysis of the satellite structure caused by Si4+ and Ca2+ substitutions in the neighborhood of the resonating iron ion indicated that the spatial correlation of Si4+ and Ca2+ is small.