Low Temperature Physics | A. S. Borovik-Romanov (Ed.)

The authors of this collection are leading members of the staff at the Institute of Physics Problems of the Academy of Sciences of the USSR, Moscow. Three of them are Members of the Academy of Sciences. The Institute was founded fifty years ago by the great contemporary physicist P. L. Kapitza. Academician L. D. Landau another giant of our time, also worked at the institute. The institute is world famous for research in low temperature physics. This is a collection of six articles on the basic achievements of the Institute during the last few years. They include the discoveries of crystallization waves in helium and quantum magnetic breakdown. The collection is intended for scientists working in solid state physics and students interested in the latest advances of quantum physics of the condensed state. This book is a part of the Advances in Science and Technology in the USSR - Physics series The book was translated from the Russian by by Valerii Ilyushchenko and was first published by Mir Publishers in 1985. Contents 1. CRYSTALLIZATION WAVES IN $latex ^{4}HE$, by A. Ya. Parshin 15 1.1. Introduction 15 1.2. Surface of a Classical Crystal 16 1.2.1. Surface Energy and Equilibrium Shape of Crystal 16 1.2.2. Surface Structure at $latex T = 0$ 17 1.2.3. Surface Structure at $latex T \neq 0$ 22 1.2.4. Some Problems of Growth Kinetics 24 1.3. Surface of a Quantum Crystal 27 1.3.1. Quantum-Rough State 27 1.3.2. Coherent Crystallization 36 1.3.3. Crystallization Waves 38 1.3.4. Sound Transmission Through a Quantum-Rough Surface 41 1.4. Experimental Investigation of Coherent Crystallization and Crystallization Waves 45 1.4.1. On the possibility of Direct Observation of Capillary Phenomena in Crystals 45 1.4.2. Optical Cryostat 47 1.4.3. Features of the Low Temperature Growth Kinetics of $latex ^{4}He$ Crystals 49 1.4.4. Techniques to Excite Crystallization Waves 55 1.4.5. Visual Observations of Crystallization Waves 60 1.4.6. Spectrum and Damping Crystallization Waves 62 1.5. Conclusion 74 References 75 2. SOUND PROPAGATION THROUGH A LIQUID-METAL INTERFACE by K. N. Zinov'eva 2.1. Introduction 78 2.2. Acoustic Phenomena at a Liquid-Solid Interface 79 2.2.1. Reflection and Transmission Coefficients of the Acoustic Energy According to the Classical Acoustic Theory [2.6] 79 2.2.2. The Khalatnikov Theory of Liquid Helium-Solid Heat Transfer. Kapitza Resistance [2.2] 82 2.2.3. The Andreev Theory of Resonance Absorption of Sound by a Metal Surface 83 2.2.4. The Generalized Acoustic Theory 85 2.2.5. Rayleigh Surface Waves 89 2.2.6. First Experiments on Reflection and Transmission Coefficients of Thermal Phonons Passing Across a Liquid Helium-Solid Interface 92 2.3. Experimental Investigations of Sound Transmission from Liquid $latex ^{4}He$ into a Metal 94 2.3.1. Experimental Procedure 94 2.3.2. Apparatus 96 2.3.3. Experiment 103 2.3.4. Results of Measurements at $latex T \geq 0.2 K$ 104 2.3.5. Results of Measurements at $latex T < 0.2 K$ 112 2.3.6. Discussion of Experimental Curves. Evaluation of Errors 115 2.3.7. Calculations Using the Generalized Acoustic Theory 116 2.3.8. Comparison of Experimental Data with the Generalized Acoustic Theory 121 2.3.9. Comparison with the Andreev Theory 128 2.4. Conclusion 129 References 130 3. INVESTIGATIONS OF $latex ^{3}HE$ SUPERFLUID PHASES BY PULSED NMR TECHNIQUE, by Yu. M. Bun'kov 132 3.1. Introduction 132 3.2. The Equipment for Producing Ultralow Temperatures 134 3.2.1. Operating Conditions 134 3.2.2. The Dilution Refrigerator 135 3.2.3. The Nuclear Demagnetization Refrigerator 141 3.3. Instability of Homogeneous Precession in $latex ^{3}He-A$ and Its Effect on Relaxation Processes 143 3.3.1. Basic Properties of the $latex ^{3}He$ Superfluid Phases 143 3.3.2. "lntrinsic" Relaxation Mechanism in Superfluid $latex ^{3}He$ 146 3.3.3. A Study of the $latex ^{3}He-A$ Free Induction Signal 149 3.3.4. Instability of Homogeneous Precession in $latex ^{3}He-A$ 156 3.3.5. Experimental Studies of an Instability in the Homogeneous Precession in $latex ^{3}He-A$ 161 3.4. A Texture Transition in $latex ^{3}He-B$ Induced by a Radio Frequency Field 164 3.4.1. Threshold Effect in Pulsed $latex ^{3}He-B$ NMR 164 3.4.2. A Texture Transition in $latex ^{3}He-B$ 167 3.4.3. Studies of the Brinkman-Smith Relaxation Mode with Parallel Plate Geometry 169 3.5. Conclusion 171 References 172 4. EXPERIMENTAL INVESTIGATIONS OF COHERENT MAGNETIC BREAKDOWN, by N. E. Alekseevskii and V. I. Nizhankouskii 174 4.1. Introduction 174 4.2. Beryllium 175 4.3. Aluminium 191 4.4. Niobium 198 4.5. Ruthenium Dioxide $latex RuO_2$ 212 4.6. Conclusion 218 References 218 5. WEAK ELECTRON LOCALIZATION AND MAGNETO-RESISTANCE OSCILLATIONS OF CYLINDRICAL NORMAL METAL FILMS by Yu. V. Shar vin and D. Yu. Sharvin 221 5. Introduction 221 5.1. An Experiment with Lithium Film 226 5.2. Experimental Technique 226 5.2.1. Experiments at 1.1 K 227 5.2.2. Experimental Observations of the Longitudinal Magnetoresistance 5.3. Oscillations of Cylindrical Films of Different Metals, and the AAS Effect 230 5.3.1. Magnesium 234 5.3.2. Cadmium 236 5.3.3. Lithium 237 5.4. Conclusion 239 References 239 6. BRILLOUIN-MANDELSHTAM SCATTERING IN MAGNETIC MATERIALS by A. S. Borovik-Romanov and N. M. Kreines 241 6.1. Introduction 241 6.2. Magnetooptical Effects and the Mechanism of Light Scattering in Magnetic Materials 243 6.3. Apparatus Samples 248 6.3.1. Apparatus 248 6.3.2. Samples 250 6.4.Spectra of Thermal Magnons in $latex CoCO_{3}$ 251 6.5.Modulation of Light by Magnetic Resonance in Magnetic Materials 255 6.5.1. General Remarks 255 6.5.2. $latex CoCO_{3}$ 257 6.5.3. $latex K_{2}CuF_{4}$ 259 6.5.4. $latex RbNiF_{3}$ [6.23] 261 6.5.5. $latex Nd_{3}Ga_{5}O_{12}$ [6.24] 265 6.6. Magnon "Bottle-Neck" Under AFMR and FMR 266 6.7. Light Scattering from Parametrically Excited Quasiparticles (Magnons and Phonons) in $latex CoCO_{3}$ 275 6.7.1. Parametrical Magnons in $latex CoCO_{3}$ 276 6.7.2. Parametrical Phonons in $latex CoCO_{3}$ 286 References Author Index Subject Index